Patent ID: 12232969

DETAILED DESCRIPTION

FIGS.1A and1Bshow two conventional approaches to total shoulder arthroplasty.FIG.1Ashows an anatomic approach in which the humeral head is replaced with an articular body64having an convex articular surface65. The glenoid of the scapula can be modified with an implant67providing a concave surface68for articulation of the humeral articular body64The humeral articular body64is secured to the humerus H using a stemless anchor4that is dedicated for and only compatible with the anatomic articular body64.

FIG.1Bshows a reverse approach in which the humerus H is fitted with an articular body84having a concave articular surface85. The glenoid region of the scapula is fitted with a spherical articular body, commonly called a glenosphere87. In this case, the concave articular surface85placed on the humerus articulates of the glenosphere87, which is fixed relative to the scapula. The reverse articular body84is mounted to a tray89that is disposed between the reverse humeral articular body84and a stem anchor83that is surgically implanted in the humerus H. The humerus H is prepared by providing access to the medullary canal of the humerus H.

One can see that the anatomic and reverse approaches generally use different hardware to secure the articular components. So, switching from an anatomic to a reverse configuration requires extraction of the stemless anchor4. The bone stock that remains after such an extraction may or may not be suitable for supporting the stem anchor83. Also, the presence of the tray89requires more of the joint space. Thus, the reverse configuration may only be suitable for some patients with large joint space or following more invasive preparation of the humerus and/or the scapula.

I. Overview of Shoulder Prosthesis Assemblies

Various embodiments disclosed herein relate to shoulder prosthesis assemblies that can beneficially lead to improved patient outcomes, for example, by reducing the volume of bone removed from the patient's humerus, reducing surgery time, improving convertability between anatomical and reverse prostheses, providing adaptability with stemmed anchors, and improving reliability of the prosthesis. In some conventional shoulder arthroplasty techniques, a humeral stem anchor may be inserted into the patient's humerus and can be configured to engage with an articular body attached to the glenoid surface. Such a stemmed anchor may present long-term fixation issues, as well as undesirable radiologic signatures such as radiolucencies, spot welds, etc. To reduce fixation problems, radiologic signatures, and surgery times associated with traditional stemmed anchors, stemless anchors can be used.

Indeed, stemless shoulder arthroplasty has become much more attractive to surgeons for a number of reasons, including shorter surgery time, less blood loss, fewer periprosthetic fractures, easier anatomic reconstructions, etc. Stemless shoulder arthroplasty has been largely limited to use in anatomic reconstructions, such that reverse reconstructions can be challenging. Moreover, providing a stemless reverse reconstruction may not be as bone conserving as anatomic reconstructions. Further, it may be challenging to insert stemless anchors in the anatomy in a way that adequately or easily secures the stemless anchor to the humerus. For example, some stemless anchors may be twisted or threaded into the anatomy.

Beneficially, various embodiments disclosed herein disclose a reverse arthroplasty stemless device that can preserve as much bone volume as similar stemmed devices. Moreover, the reverse arthroplasty stemless devices disclosed herein can be converted to anatomical devices in some embodiments. In various embodiments, the stemless devices can be incorporated into one or more kits that include stemmed anchors, so that the clinician can select the appropriate prosthesis (e.g., stemmed or stemless) in the operating room after observing the patient's degree of humeral damage.

FIG.2Ais a schematic diagram of a total arthroplasty system comprising an arthroplasty kit100that can be used to perform anatomic or reverse arthroplasty, or to convert from one of anatomic to reverse or reverse to anatomic arthroplasty, according to various embodiments. The kit100can comprise one or a plurality of stemless humeral anchors103, one or a plurality of stemmed humeral anchors113, and one or a plurality of articular components161. For example, the kit100can include a plurality of bowl-shaped stemless humeral anchors104with finned distal portions. As explained herein, the stemless humeral anchors104can have a tapered profile in which a distal portion105of the anchor104tapers significantly compared with a proximal portion107of the anchor104, such that the distal portion105is significantly laterally or radially narrower than the proximal portion107. The relatively narrow distal portion105of the anchor104can beneficially preserve humeral bone volume by occupying less space within the humerus. The kit100may additionally, or alternatively, include a plurality of bowl-shaped stemless humeral anchors108. The distal portion105of the bowl-shaped humeral anchors108may have a smaller taper as compared with the humeral anchors104. The larger distal portion105of the humeral anchors108can serve a bone-filling function. A more voluminous distal portion105occupies more of the bone volume distal the humeral resection. This can be beneficial for example when the bone quality toward the center of the metaphysis would not sufficiently support the more tapered anchor104but the bone quality toward the cortical portion would sufficiently support the anchor108.

As shown inFIG.2A, the stemless anchors103can be provided in a plurality of sizes to accommodate patients of different sizes, different degrees of bone damage to the humerus, etc. In some embodiments, the lateral size of the stemless anchors103may vary so as to fit within different-sized resections of the humerus. In some embodiments, a length l1of the stemless anchors103may also vary so as to extend into the humerus by a depth that the clinician selects based on the particular patient being treated.

The kit100can also include one or a plurality of stemmed humeral anchors113. The kit100can include one or more humeral stem anchors112, each of which includes a proximal metaphysis portion120and an elongate diaphysis portion (e.g., stem portion)116extending therefrom. In some embodiments, the kit100can also include a trauma or fracture stem anchor140, which can be used in patients that have experienced a fracture of the humerus H. The stemmed humeral anchors113may be used in patients in which stemless anchors103may not be adequately secured to the humerus, for example, in patients that have experienced severe bone loss. As with the stemless anchors103, the kit100can include stemmed anchors113having a plurality of different sizes, e.g., different lateral sizes and/or different lengths l2. For example, as shown inFIG.2A, the stemmed humeral anchors113can have respective lengths l2that are longer than the lengths l1of the stemless anchors103. In various embodiments, the lengths l2of the stemmed humeral anchors can be in a range of 55 mm to 125 mm. By contrast, the shorter lengths l1of the stemless humeral anchors103can be in a range of 16 mm to 28 mm. In various embodiments, stemmed humeral anchors113,140can be configured to reach into the intramedullary canal of the humerus H for additional anchorage.

Beneficially, the kit100can comprise one or a plurality of shared humeral components that be used with either the stemless humeral implants103or the stemmed humeral implants113, depending on which implant103or113would be more appropriate for a particular patient's humeral anatomy. For example, the shared humeral components of the kit100can comprise a plurality of inserts161that can be used in conjunction with either the stemless implants103or the stemmed implants113.

For example, the kit100can include an anatomic articular component160configured to mechanically couple to both the stemless humeral implants103and the stemmed humeral implants113. The clinician may select the anatomic articular component160for procedures in which an anatomic reconstruction is suitable. The anatomic articular component160can comprise a coupler168and an articular body164(anatomical) configured to mechanically engage the coupler168. As shown inFIG.2A, the articular body164for the anatomic articular component160can comprise a rounded, convex surface configured to engage a glenoid surface of the patient. As explained herein, the coupler168can serve to mechanically connect the anatomical articular body164(e.g., a rounded or essentially spherical surface) to either a stemless humeral implant103or a stemmed humeral implant113, depending on the patient's humeral bone structure. The articular body164and the coupler168can comprise a metal, such as cobalt, chrome, or titanium. In some embodiments, the articular body comprises a pyrocarbon layer on at least the articular surface. In various embodiments, the kit100can include anatomic articular components160having a plurality of sizes.

The kit100can also include a reverse articular component180configured to mechanically couple to both the stemless humeral implants103and the stemmed humeral implants113. The clinician may select the reverse articular component180for procedures in which a reverse anatomic reconstruction is suitable. The reverse articular component180can comprise a reverse articular body184and a locking device188configured to secure the reverse articular component180to a stemless humeral implant103or a stemmed humeral implant113, depending on the clinician's recommendation during the procedure. As shown, the reverse articular body184can comprise a rounded concave surface (e.g., essentially spherical) configured to engage with a glenosphere connected to the glenoid of the patient. In addition, in some embodiments, the kit100can include a wear resistant reverse articular component180A, which may be generally similar to the reverse articular component180but may further be formed to include vitamin E to promote long-term compatibility with the patient's bone structure. The reverse components180,180A can comprise a polymer, including, for example, ultra high molecular weight polyethylene. In various embodiments, the kit100can include reverse articular components180,180A having a plurality of sizes.

During an arthroplasty procedure, the clinician may inspect the bone structure of the humerus and/or the scapula to determine whether the anatomy is suitable for a stemless or stemmed humeral anchor, and whether the anatomy is suitable for an anatomical or reverse anatomical reconstruction. Beneficially, the kit100shown in FIG.2A can provide the clinician with a total arthroplasty system including components that are compatible with stemless or stemmed anchors, and with anatomical or reverse anatomical constructions. For example, during a procedure, the clinician may observe that the patient has sufficient humeral bone structure so that a stemless anchor103may be used to reduce the damage to the patient's anatomy. The clinician can select a bowl-shaped anchor104or108, and can select the corresponding size appropriate for the patient. The clinician may also elect whether to proceed with an anatomical reconstruction or a reverse construction, and can accordingly select either the anatomical articular component160or the reverse articular component180,180A.

Similarly, if during a shoulder arthroplasty procedure, the clinician determines that the patient's bone structure is damaged or otherwise more suited to a stemmed anchor113, then the clinician can select an appropriately sized stemmed anchor113. The clinician can further select whether to proceed with an anatomical reconstruction or a reverse construction, and can accordingly select either the anatomical articular component160or the reverse articular component180,180A. Beneficially, the kit100ofFIG.2Aincludes interchangeable or interoperable components that can be used in stemmed or stemless anchors, and with anatomical or reverse anatomical reconstructions. Because the shared humeral inserts161(e.g., anatomical or reverse anatomical articular bodies) can be used with either the stemless or stemmed anchors103,113, the clinician can make, or change, reconstruction decisions during surgery. The kit100can accordingly enable the clinician to quickly determine the reconstruction procedure most suitable for a patient and can provide the clinician with the components to be used for that reconstruction procedure.

As explained above, for humeral fractures, the kit100can also include one or more trauma stems140. As explained herein in connection withFIGS.7F-7G, the coupler168can comprise a proximal extension163A configured to connect to the articular body164and a distal extension163B. The distal extension163B for the fracture stem140can be received within a recess217of the fracture stem140for anatomical reconstructions. The disc or middle portion162disposed between the proximal extension163A and the distal extension163B can be eliminated since the recess217is elevated toward the resection plane. In a modified embodiment, the recess217is recessed from (e.g., extends distally from) a distal end of the recess216, similar to what is shown inFIGS.7F and7G. In those embodiments, the disc or middle portion162provides a spacer function in use in the trauma stem140. Additional details of trauma stems may be found throughout International Application No. PCT/US2015/065126, filed Dec. 15, 2015, the entire contents of which are hereby incorporated by reference herein in their entirety and for all purposes.

FIG.2Bis a schematic diagram of a total arthroplasty system comprising an arthroplasty kit100A that can be used to perform anatomic or reverse arthroplasty, or to convert from one of anatomic to reverse or reverse to anatomic arthroplasty, according to another embodiment.FIG.2Cis a schematic view showing a stemless humeral anchor104visually overlaid with a humeral stem anchor112(not physically disposed within the stem anchor112). Unless otherwise noted, the components of the kit100A can be generally similar to like-numbered components ofFIG.2A, except reference numerals inFIGS.2B and2Chave been appended with the letter “A.” As shown inFIG.2B, the kit100A can comprise a humeral stem anchor112and a stemless humeral anchor104A. As shown in the overlay ofFIG.2C, an exterior surface214A of the stemless anchor104A can occupy or define less volume than the metaphysis portion120of the stemmed anchor112.

Accordingly, during a procedure, the stemless anchor104A may be inserted into the metaphyseal portion of the humerus. If the clinician determines that the bone structure is damaged such that the stemless anchor104A is not adequately secured to the humerus, then the clinician can remove the stemless anchor104A and insert the stemmed anchor112A into the humerus. The clinician can enlarge the opening into the humerus to accommodate the wider metaphysis portion120of the stemmed anchor112A. Beneficially, because the exterior surface214A of the stemless anchor104A occupies a relatively small volume (e.g., less volume of the metaphyseal profile of the humerus than the metaphysis portion120occupies), the clinician can have the ability to enlarge the resection without compromising the patient's humeral bone structure. It should be appreciated that, although the metaphysis portion120of the stem anchor112A is wider than the finned portion of the stemless anchor104A, the proximal end (e.g., the collar, which is described below) may have substantially the same diameter or width, such that the proximal ends may fit within the same size resection.

II. Examples of Humeral Anchors

FIGS.3-4Eillustrate stemless anchor103comprising a stemless bowl-shaped humeral anchor108B, according to one embodiment. The bowl-shaped humeral anchor108B can have a distal portion in which at least a portion of the exterior surface has a curved (e.g., convex) profile. The distal portion of bowl-shaped humeral anchors may be wider than corresponding distal portions of finned humeral anchors. Unless otherwise noted, reference numerals inFIGS.3-4Eillustrate components similar to those shown inFIGS.1A-2C, except the reference numerals are appended with the letter “B.”FIG.3is a schematic side view of the stemless humeral anchor108B shown secured within the humerus H, with the humerus H illustrated as semi-transparent for ease of illustration. It should be appreciated that, althoughFIG.3shows the stemless anchor108B, any of the other stemless anchors103described herein may be similarly inserted into the humerus H as shown inFIG.3. As explained herein, in the illustrated embodiment, the anchor108B may be inserted into the humerus H by non-rotational, direct insertion into the humerus H. In other reconstruction systems, humeral anchors may be inserted into the humerus H using a rotational motion, for example, to thread, screw, or drill the anchor into the humerus H. In such systems, the need to rotate the anchor may complicate the surgical process, such that the clinician must either manually rotate the anchor into position, or use other instruments to rotate the anchor into the humerus H. Accordingly, the disclosed embodiments may beneficially enable direct non-rotational insertion into the humerus H to simplify the replacement procedure.

Furthermore, as shown inFIG.3, and as explained below, the stemless anchor108B can include a collar244B at a first or proximal end204B of the anchor108B. As shown inFIG.3, the collar244B may be provided generally flush with the resection surface RS. In other embodiments, the collar244B may be provided slightly above the resection surface RS. In still other embodiments, the collar244B may be provided slightly below the resection surface RS. An insert161(which is illustrated as a reverse articular component180inFIG.3) can be inserted into a recess216B of the stemless anchor108B. As explained above, the reverse articular component180can be configured to engage with a glenoid sphere. In the illustrated embodiment, at least portions of the recess216B (see below) and portions of the insert161can be disposed below the resection surface RS. Providing portions of the insert161(e.g., portions of the articular body184, such as portions configured for engaging the recess216B or even a portion of the concave surface) below the resection surface RS can beneficially improve the surgical reconstruction since the prosthesis may more closely match the natural anatomy of the humerus H.

FIG.4is a schematic side view of the stemless humeral anchor108B shown inFIG.3.FIG.4Ais a sectional view of the anchor108B shown with the insert161disposed within the anchor108B ofFIG.4, taken along section4A-4A.FIG.4Bis a schematic top perspective view of the anchor108B ofFIG.4A.FIG.4Cis a schematic bottom perspective view of the anchor108B ofFIG.4A.FIG.4Dis a schematic side sectional view of the anchor108B ofFIG.4A.

The anchor108B ofFIGS.3-4Dcan have a first end204B and a second end208B spaced from the first end204B. The first end204B can be a proximal end. The second end208B can be a distal end. The anchor108B can comprise a monolithic body. The anchor108B can comprise a wall213B having an exterior surface214B facing outwardly from a central portion of the anchor108B and an interior surface212B facing inwardly toward the central portion of the anchor108B. The interior surface212B and the exterior surface214B can extend between the first and second ends204B,208B of the anchor108B. The inner surface212B can be disposed about a recess216B disposed between the first and second ends204B,208B. The recess216B can be configured to secure a shoulder articular body or component (such as the reverse articular component180) to the interior surface212B. As explained above, a collar244B can be provided at or near the first end204B. The collar244B can comprise a transverse surface configured to engage a humeral bone layer exposed by resection (e.g., at or near the resection surface RS) or other preparation when the humeral anchor108B is implanted to resist subsidence.

As shown inFIG.4D, the interior surface212B may comprise one or more tapered surfaces for engaging an articular assembly, such as any of the inserts161shown inFIG.2A. In the embodiment ofFIG.4D, for example, the interior surface212B can comprise a first tapered surface212B′ disposed towards the first end204B and a second tapered surface212B″ disposed towards the second end208B. As illustrated inFIG.4D, the first tapered surface212B′ can extend generally between the first end204B and a shoulder215B disposed laterally inward from the wall213B. In various embodiments, the first tapered surface212B′ can be angled or tapered to receive an insert161comprising a shoulder articular body, e.g., the anatomical articular body160or the reverse articular body180. InFIG.4D, the first tapered surface212B′ can be angled such that the recess216B is wider at the first end204B than at locations towards the second end208B (e.g., than at the shoulder215B). The second tapered surface212B″ can be angled or tapered to engage with an adaptor460(seeFIG.4E) for coupling the anchor108B to a stemmed anchor113. InFIG.4D, the second tapered surface212B″ can extend from the shoulder215B to the second end208B. In some embodiments, the recess216B can be wider (or can be approximately the same width) at the second end208B than at the shoulder215B. In other embodiments, the recess216B can be wider at or near the shoulder215B than at the second end208B.

As shown inFIGS.4B and4D, the interior surface212B can comprise one or a plurality of slots264B sized and configured to engage an insert161(such as the articular components160,180). As explained below, for example, the slots264B can engage or receive corresponding ridges189A,191A of the insert161(see, for example,FIG.4J). As explained herein, the slots264B can limit rotation of the insert161relative to the anchor108B. The slots264B can also guide the advancement of the insert161into an upper portion of the recess216B. The slots264B can be disposed vertically along the interior surface212B and can be circumferentially spaced from one another. In the embodiment ofFIGS.4B and4D, the slots264B can extend from a location proximate the first end204B towards the shoulder215B. Further, the interior surface212B can comprise a groove300B extending circumferentially about the recess216B. The groove300B can be sized and configured to receive a locking ring of an articular body assembly (e.g., any of the inserts161described herein).

As shown inFIGS.4,4C, and4D, the exterior surface214B can comprise a first tapered portion292B disposed about the first end204B and a second tapered portion296B disposed about a portion of the humeral anchor108B between the first tapered portion292B and the second end208B of the anchor108B. The first tapered portion292B can have a first angle disposed away from a longitudinal axis y extending through the first end204B to the second end208B. The second tapered portion296B can have a second angle disposed away from the axis y. In some embodiments, the second angle can be greater than the first angle. In the illustrated embodiment, the first and second tapered portions292B,296B can be discontinuous from one another. For example, as shown inFIGS.4C and4D, a lateral projection248B can provide at least a portion of the discontinuity between the tapered portions292B,296B. Further, the lateral projection248B can assist in reducing subsidence. Also, providing a multiple stage (e.g., two-stage) taper using the tapered portions292B,296B can ease the insertion of the anchor108B into the humerus H. For example because the second tapered portion296B has a lower profile than the first tapered portion292B, the second tapered portion can be fit into a smaller space in the resected humerus. Such placement can be achieved with less reaming than were the second tapered portion296B along the same taper as the first tapered portion292B.

In addition, the stemless humeral anchor108B can comprise a porous surface272B disposed on the exterior surface214B. The porous surface272B can be configured to foster the growth of bone into the porous surfaces272B to improve integration of the anchor108B into the anatomy. Further, the porous surfaces272B can be bounded by one or more non-porous edges276B that can protect the porous surfaces272B. InFIG.4, for example, an upper non-porous edge276B can separate the porous surfaces272B that are disposed on the tapered portions292B,296B, respectively. As shown the upper non-porous edge276B can be disposed between the porous surface272B disposed on the tapered portion292B and the second end208B. A lower non-porous edge276B can be disposed near the second end208B. Beneficially, the non-porous edges276B can protect the porous surfaces272B during insertion of the anchor108B into the bone. The portion of the anchor108B underlying the non-porous surface276B also can provide one or both of enhanced strength against load directed transverse thereto.

The anchor108B can also include a plurality of struts304B disposed about or along the exterior surface214B. For example, as shown inFIG.4C, the struts304B can be disposed vertically or along or generally aligned to the longitudinal axis y and can be disposed on the first tapered portion292B of the anchor108B. The struts304B can have an external surface that is tapered as in the first tapered portion292B. As shown inFIG.4C, the struts304B can extend from the first end204B towards the second end208B between the ends204B,208B (e.g., from the collar244B to the lateral projection248B). The struts304B can be circumferentially spaced from one another with the porous surface272B being disposed between adjacent struts304B. There can be several porous surfaces272B arrayed about the periphery of the first tapered portion292B, with struts304B disposed therebetween. The struts304B can beneficially assist in reducing, minimizing, or eliminating rotation of the humeral anchor108B. In some embodiments, the struts304B may be configured to improve the strength of the anchor108B.

In addition, as shown inFIGS.4and4C, the anchor108B can include one or a plurality of fins306B disposed along the exterior surface214B. As shown inFIG.4C, the fins306B can be circumferentially spaced from one another with the porous surface272B intervening between adjacent fins306B. As shown, the fins306B can extend from the lateral projection248B towards the second end208B. The fins306B can be angled so as to be thicker near the lateral projection248B and thinner nearer the second end208B. The fins306B can beneficially assist in reducing rotation of the anchor108B.

FIG.4Eillustrates an exploded view that shows the stemless anchor108B configured to connect to an adaptor460for coupling to a stemmed anchor113,140. The adaptor460can comprise a first opening466at a first end and a second opening468at a second end. The second end208B of the anchor108B can be disposed around the outer periphery of the adaptor460to couple with the adaptor460. The second opening468can be disposed about a joining member448(such as a projection or male joining member) of the stemmed anchor113to mechanically couple the stemless anchor108B to the stemmed anchor113. Accordingly, in various embodiments, the stemless anchor108B can be used in both stemless and stemmed reconstructions. Additional embodiments of a stem adaptor and kits including one or more stems, adaptors, and related components may be found throughout International Patent Application No. PCT/US2017/028470, filed on Apr. 19, 2017, the entire contents of which are hereby incorporated by reference herein in their entirety and for all purposes. Furthermore, in various embodiments, the coupler168(and hence the articular body164) may couple to the stemmed anchor to provide an anatomical reconstruction for the fracture stem. Additional details of using a fracture stem with components similar to the coupler168may be found throughout International Patent Application No. PCT/US2015/065126, the entire contents of which are hereby incorporated by reference herein in their entirety and for all purposes.

FIGS.4F-4Killustrate an embodiment of an insert161comprising a reverse articular component180A configured to be used in a reverse shoulder prosthesis by coupling to a glenoid sphere or glenosphere. For example,FIG.4Fis a top perspective view of the reverse articular component180A.FIG.4Gis a bottom perspective view of the reverse articular component180A shown inFIG.4F.FIG.4His a schematic side view of the reverse articular component180A shown inFIG.4F.FIG.4Iis a schematic side sectional view of the reverse articular component180A shown inFIG.4F.FIG.4Jis a magnified perspective view of a portion of the reverse articular component180A shown inFIG.4F. Unless otherwise noted, the components ofFIGS.4F-4Kmay be the same as or generally similar to like numbered components ofFIG.2A, but with the reference numerals appended with the letter “A.” As explained above in connection withFIG.2A, the reverse articular component180A can comprise a reverse articular body184A coupled to or formed with a locking device188A configured to secure the articular component180A to either a stemless anchor103or a stemmed anchor113.

The reverse articular body184A can comprise a concave surface CV extending distally from a raised rim187A. The concave surface CV can comprise a curved surface, which may be generally spherical and shaped to cooperate with a glenoid sphere coupled to a glenoid surface of the patient. When the insert161is secured within the humerus, at least a portion of the articular body184A can be disposed below the resection surface RS. For example, in some embodiments, a connection portion and in some cases, a portion of the concave surface CV can be disposed below the resection surface RS. As an example, at least a distalmost portion of the concave surface CV can be disposed below the resection surface RS. A pedestal portion181A can extend distally from the upper portion of the articular body184A. The pedestal portion181A can be narrower than (or have a smaller diameter than) the raised rim187A. Furthermore, as shown inFIGS.4H and4I, a sloped surface185A can extend between the pedestal portion181A and a lower portion of the raised rim187A. The sloped surface185A can engage with the interior surface of the stemless or stemmed humeral anchors103,113so as to be slidably inserted into a recess of a humeral anchor.

The locking device188A can be provided on the pedestal portion181A and can comprise a snap ring183A disposed within an outer annular groove190A of the pedestal portion181A. As shown inFIG.4J, the pedestal portion181A can comprise an upper ridge189A spaced apart from a lower ridge191A with the outer groove190A disposed between the ridges189A,191A. Returning toFIG.4A, the ridges189A,191A can engage and be received within the corresponding slots264B to limit or prevent rotation of the insert161relative to the humeral anchor in which it is received. As shown, the ridges189A,191A can be disposed vertically (e.g., extending along the axis y) and can be circumferentially spaced from one another.

FIG.4Kis a schematic top plan view of the snap ring183A shown inFIGS.4F-4J.FIG.4Lis a schematic side sectional view of a portion of the snap ring183A taken along section4L-4L. As shown inFIG.4K, the snap ring183A can comprise a partially annular undulating ring. For example, the ring183A can comprise thicker portions194A alternately disposed between laterally thinner portions193A. As shown, the thinner portions193A can comprise concave outer surfaces, and the thicker portions194A can comprise convex outer surfaces, such that an inflection point or discontinuity is disposed between the portions193A,194A. Further, a gap195A can be disposed between opposing ends of the ring183A to define the partially annular, undulating structure. As shown inFIG.4L, a thickness/of the ring183A may be generally constant across its path length in some embodiments.

Beneficially, the undulating shape of the snap ring183A can be configured to ensure a relatively constant insertion force upon insertion of the reverse articular body184A into the anchor108B across a range of sizes. For example, a first humeral anchor108B can have a recess216B of a first size. A first snap ring183A can be sized to engage the groove300B of the first humeral anchor108B. A second humeral anchor108B can have a recess216B of a second size larger than the first size. A second snap ring183A can be sized to engage the groove300B of the second humeral anchor108B. In a typical annular snap-ring, the larger size snap ring would be more flexible and would be insertable under a lower force. The smaller snap ring would be more rigid and would requires a higher insertion force. Similarly, the larger snap ring would be subject to dislodgement under a lower load than the smaller snap ring. The undulating design provides a more uniform insertion force for an insert161with a smaller snap ring and for an insert161with a larger snap ring. Similarly, the undulating snap ring provides a more consistent dislodgement force for different sizes. This more uniform performance provides more consistency and familiarity among a kit of inserts161.

Turning toFIGS.5A-5C, another embodiment of a bowl-shaped stemless humeral anchor108C is illustrated.FIG.5Ais a schematic top perspective view of the bowl-shaped stemless humeral anchor108C.FIG.5Bis a schematic bottom perspective view of the anchor108C ofFIG.5A.FIG.5Cis a schematic side sectional view of the anchor108C ofFIG.5A. Unless otherwise noted, the components ofFIGS.5A-5Cmay be the same as or generally similar to like numbered components ofFIGS.1A-4E, with the reference numerals appended with the letter “C.” For example, as withFIGS.4-4E, the anchor108C can comprise a bowl-shaped anchor. As withFIGS.4-4E, the anchor108C can comprise a monolithic body. Unlike the embodiment ofFIGS.4-4E, however, the anchor108C includes a second end portion208C that is enclosed. For example, as shown inFIG.5B, a lower wall311can be provided at the second end portion208C to enclose the anchor108C such that bone is not disposed within the anchor108C. InFIGS.4-4E, the second end208B comprises an opening. The opening in the second end208B can be enclosed with a separate component. As shown inFIG.5B, a plurality of second fins307C can be provided proximal the second end208B and disposed within a cavity309C at the second end208C. As shown, the fins307C can be disposed radially outward (for example, in spoke-like fashion) from a central portion and can extend to an inner wall of the cavity309C. The second fins307C can provide further anti-rotation capabilities for the anchor108C. Furthermore, the cavity309C can provide space between adjacent fins307C so as to enable bone ingrowth between the fins307C. As compared with the anchor108B ofFIGS.4-4E, inFIGS.5A-5C, the second tapered portion296C can be tapered at a higher angle as compared with the portion296B, which can reduce the volume of bone to be removed. In various embodiments, for example, the tapered portion296C can have a taper at an angle in a range of 1 to 15 degrees, or in a range of 2 to 10 degrees, e.g., about 5 degrees. This can simplify the procedure and also can preserve bone stock for subsequent procedures.

Moreover, as shown inFIG.5C, the shoulder215C can extend farther inwardly than the shoulder215B, so as to define a second cavity217C disposed below or distal the cavity216C (also called a first cavity). As explained in more detail herein, the second cavity217C can be sized and shaped to receive a portion of coupler168A configured to enable the anchor108C to convert from a reverse reconstruction to an anatomical reconstruction. Although not illustrated, a reverse articular component similar to the component180A may be engaged with the interior surface212C of the anchor108C in a manner similar to that described above in connection withFIGS.4-4K.

FIGS.5D-5Hillustrate an embodiment in which the stemless anchor108C can be configured for use with an anatomical articular component160A. In particular,FIG.5Dis a schematic side view of the anatomical articular component160A connected to the stemless anchor108C ofFIGS.5A-5C.FIG.5Eis a schematic perspective sectional view of the component160A ofFIG.5D.FIG.5Fis a schematic bottom perspective view of an articular body164A, according to some embodiments.FIG.5Gis a schematic top perspective view of a coupler168A, according to some embodiments.FIG.5His a schematic bottom perspective view of the coupler168A ofFIG.5G. Unless otherwise noted, components related to the articular component160A may be the same as or generally similar to like-numbered components ofFIG.2A, but appended with the letter “A.”

As explained above, the anchor108C can be used in conjunction with a reverse anatomical articular component180A, in a manner similar to that explained above. Beneficially, the anchor108C may also be used in conjunction with an anatomical component160A for use in an anatomical shoulder reconstruction. For example, the anatomical articular component160A can include an articular body164A and a coupler168A, which may be generally similar to the articular body164and coupler168ofFIG.2Aunless otherwise noted. As shown inFIGS.5E and5F, the articular body164A can comprise a spherical head portion165having a convex, generally spherical surface profile. The articular body164A can further include an elongate member166extending from the spherical head portion165.

Turning toFIGS.5G and5H, the coupler168A can comprise a proximal surface167, a distal surface169, and a hole163extending from the proximal surface167towards the distal surface169. In the illustrated embodiment, the hole163comprises a through hole but in other embodiments the hole163can comprise a blind hole. As shown inFIG.5E, the elongate member166of the articular body164A can be inserted into the hole163to connect and align the articular body164A with the coupler168A. Moreover, as shown inFIGS.5G-5H, in some embodiments, a locking device188′ can be used to connect the coupler168A to corresponding interior surfaces212C of the anchor108C. For example, a locking ring (not shown) may be disposed in an outer groove190to secure the coupler168A to the anchor108C. Upper and lower ridges189,191can be used to engage with the corresponding slots of the anchor108C, and can limit relative rotation between the coupler168A and the anchor108C.

Turning toFIGS.5I-5J, one embodiment of a stemmed humeral anchor112A is illustrated.FIG.5Iis a front perspective view of the stemmed humeral anchor112A, according to one embodiment.FIG.5Jis a rear perspective view of the stemmed humeral anchor112A ofFIG.5I. The components of the stemmed humeral anchor112A can be the same as or generally similar to the anchor112shown inFIG.2A, with the components appended with the letter “A.” For example, as withFIG.2A, the anchor112A can comprise a diaphysis portion116A (or stem) and a metaphysis portion120A integrally and monolithically formed with the diaphysis portion116A. Beneficially the metaphysis portion120A of the anchor112A can have interior and exterior surfaces that are generally similar to the anchor108C described and illustrated above. Thus, because the interior and exterior surfaces of the metaphysis portion120A may be similar to the surfaces of the anchor108C, the inserts161shown inFIG.2Acan be inserted to provide a full arthroplasty system for both reverse and anatomical shoulder replacement procedures, and for both stemless and stemmed reconstructions. For example, both the anatomic articular component160and the reverse articular component180ofFIG.2Acan be inserted into the metaphysis portion120A.

In various embodiments, the diaphysis portion116A or stem can be disposed along a longitudinal axis disposed at an angle L to a planar surface101of an end of the metaphysis portion120A. This angle L is sometimes referred to as inclination angle. The kit100ofFIG.2Acan comprise stemmed anchors112A having a plurality of sizes, and a plurality different angles L. For example, in some embodiments, the stemmed anchors112A can be disposed at an angle L in a range of 120 degrees to 150 degrees to the planar surface. For example, the kit100can comprise at least one anchor112A having an angle L in a range of 130 degrees to 140 degrees, e.g., about 135 degrees, and at least another anchor112A having an angle L in a range of 140 degrees to 150 degrees, e.g., about 145 degrees. In some embodiments, the anchor112A to be selected by the clinician can be patient-specific.

FIG.5Kis a schematic side view of a stemmed anchor112B having a diaphysis portion116B (or stem) and a metaphysis portion120B integrally and monolithically formed with the diaphysis portion116B. The stemmed anchor112B can be similar to the stemmed anchor provided by assembling the components shown inFIG.4E. As shown inFIG.5K, the metaphysis portion120B can be configured to interact or support any of the inserts161and anchors disclosed herein. In various embodiments, depending on the size of the patient or the extent of bone injury, it may be desirable to provide pre-determined humeral offsets between the humerus H and various portions of the anchor, in order to accommodate different sizes for the implant.

As shown inFIG.5K, for example, the stem or diaphysis portion116B can comprise a longitudinal stem axis Syextending along a longitudinal axis of the diaphysis portion116B. The metaphysis portion120B can comprise interior surfaces similar to those described above in connection with the stemless anchors described above. The diaphysis portion116B can comprise a concave surface CV and an axis Aypassing through a central point on the concave surface CV. The diaphysis portion116B may have a central axis Cypassing perpendicular to the concave surface CV. A distance between the axes Ayand Sycan be based on the anatomy of the patient. Thus, in various embodiments, the clinician can select a size of the anchors based at least in part on a distance between an axis of the stem (Sy) and an axis (Ay) that intersects the central axis Cyof the anchor. In various embodiments, the clinician can design the stemmed anchor112B to provide a desired distance between an axis of the stem (Sy) and an axis (Ay) that intersects the central axis Cyof the anchor. In some embodiments, the clinician can select an anchor based at least in part on a distance between an axis of the stem (Sy) and the central lower point of the concave surface (CV) of the device or based on an axis extending through a geometric center of the metaphysis portion120B and perpendicular to a proximal plane thereof.

FIGS.6A-6Fillustrate another embodiment of a stemless humeral anchor104configured for use in both anatomical and reverse anatomical shoulder arthroplasty procedures. The stemless humeral anchor104can comprise the same humeral anchor104as that shown inFIGS.2A-2B. Further, unless otherwise noted, other components ofFIGS.6A-6Fmay be the same as or generally (e.g., functionally) similar to like-numbered components ofFIGS.3-5J, but without any letters appending the reference numerals. As explained above in connection withFIG.2A, the anchor104ofFIGS.6A-6Fcan comprise a bowl-shaped stemless anchor with a finned distal portion which can beneficially be used in stemless procedures for reducing or minimizing bone less, as the diameter or width of the distal portion105may be less than the diameter or width of the proximal portion107.

FIG.6Ais a schematic perspective view of a prosthesis comprising the humeral anchor104connected to an anatomical articular component160comprising an anatomical body164with a convex surface. As explained above, the articular component160ofFIG.6Acan be used in an anatomical shoulder replacement procedure. In such procedures, the anatomical body164can engage with a concave surface coupled to the glenoid surface of the patient.

By contrast,FIG.6Bis a schematic perspective view of a prosthesis comprising the humeral anchor104connected to a reverse articular component180comprising a reverse articular body184having a concave surface. As explained above, the reverse articular component180ofFIG.6Bcan be used in a reverse anatomical shoulder replacement procedure. In such procedures, the reverse articular body184can engage with a convex surface coupled to the glenoid surface of the patient. Accordingly, the anchor104can be used in both anatomical and reverse anatomical procedures.

FIG.6Cis a schematic perspective view of the humeral anchor104ofFIGS.6A-6Bhaving a first size.FIG.6Dis a schematic perspective view of the humeral anchor104having a second size different than (e.g., smaller than) the first size.FIG.6Eis a top plan view of the humeral anchor104ofFIGS.6A-6B.FIG.6Fis a schematic side sectional view of the humeral anchor104, taken along section6F-6F. The kit100can comprise a plurality of the anchors104in a corresponding plurality of different sizes. The anchor104shown inFIGS.6C-6Dcan comprise an exterior surface114having a plurality of struts304, a porous surface272, one or more non-porous edges276, and a collar244, which may function in a generally similar manner to like-numbered components ofFIGS.3-4E. Similarly, the anchor104can comprise a first portion292and a second portion296at the exterior surface114. In some embodiments, the first and second portions292,296may not be tapered (e.g., may be generally cylindrical) or may be only slightly tapered. The first and second portions292,296can be configured to engage with humeral bone layers upon insertion into the anatomy.

Unlike the embodiment ofFIGS.3-4E, however, the anchor104may comprise a finned anchor, as opposed to a bowl-shaped anchor108. As shown inFIGS.6C-6D, for example, the lateral projection248can position the second portion296to be laterally inset from the first portion292. One or a plurality of fins306can extend radially outwardly from the second portion296. As shown the fins306can be thicker near the lateral projection248that at or near the second end208. The fins306can serve as anti-rotation features for the anchor104. Further, the anchor104can comprise one or more apertures277. The apertures277can be used to remove the anchor104in the event of problems. For example, if the anchor104is to be removed, a tool can be inserted through the aperture(s)277to cut soft tissue disposed distal the aperture(s)277to assist in freeing the anchor104from the humerus H.

Turning toFIGS.6E and6F, the lateral projection248may serve to define a second distal recess217that is below or distal to the first recess116. As shown inFIG.6F, for example, the first recess216may be wider and larger than the second recess217. As explained above, in some embodiments, the first recess216may be defined by generally cylindrical or only slightly tapered walls. Similarly, the second recess217may be defined by generally cylindrical or only slightly tapered walls. As explained herein, in some embodiments, the second recess217can be sized and shaped to receive a portion of the coupler160to convert the reverse anatomical reconstruction device ofFIG.6Bto the anatomical reconstruction device ofFIG.6A. A tapered surface260disposed on the exterior surface114can taper the diameter of the anchor104such that the diameter or width is smaller at the second end208than at the first end204.

FIGS.7A-7Eillustrate another embodiment of a stemless humeral anchor108configured for use in both anatomical and reverse anatomical shoulder arthroplasty procedures. The stemless humeral anchor108can comprise the same humeral anchor108as that shown inFIG.2A. Further, unless otherwise noted, other components ofFIGS.7A-7Emay be the same as or generally (e.g., functionally) similar to like-numbered components ofFIGS.3-6F, but without any letters appending the reference numerals. As explained above in connection withFIG.2A, the anchor108ofFIGS.7A-7Ecan comprise a bowl-shaped anchor in which the larger distal portion105of the humeral anchor108can serve a bone-filling function, as explained above.

FIG.7Ais a schematic perspective view of a prosthesis comprising the humeral anchor108connected to an anatomical articular component160comprising an anatomical body164with a convex surface. As explained above, the articular component160ofFIG.7Acan be used in an anatomical shoulder replacement procedure. In such procedures, the anatomical body164can engage with a concave surface coupled to the glenoid surface of the patient. The anchor108can include a bowl-shaped anchor body having a first proximal portion and a second distal portion coupled with the first proximal portion, with the bowl-shaped anchor body shaped to fill at least a portion of a metaphysis of a humerus of a patient.

By contrast,FIG.7Bis a schematic perspective view of a prosthesis comprising the humeral anchor108connected to a reverse articular component180comprising a reverse articular body184having a concave surface. As explained above, the reverse articular component180ofFIG.6Bcan be used in a reverse anatomical shoulder replacement procedure. In such procedures, the reverse articular body184can engage with a convex surface coupled to the glenoid surface of the patient. Accordingly, the anchor108can be used in both anatomical and reverse anatomical procedures.

FIG.7Cis a schematic side view of the humeral anchor108ofFIGS.7A-7B.FIG.7Dis a schematic top perspective view of the humeral anchor108ofFIG.7C.FIG.7Eis a schematic perspective side sectional view of the humeral anchor108ofFIG.7C. As with the embodiment ofFIGS.3-6F, the embodiment ofFIGS.7A-7Ecan include an exterior surface114that includes a plurality of struts304, a porous surface272, one or more non-porous edges276, and a collar244, which may function in a generally similar manner to like-numbered components ofFIGS.3-4E. Similarly, the anchor108can comprise a first portion292and a second portion296at the exterior surface114. In some embodiments, the first and second portions292,296may not be tapered (e.g., may be generally cylindrical) or may be only slightly tapered. The first and second portions292,296can be configured to engage with humeral bone layers upon insertion into the anatomy as explained herein.

Furthermore, a plurality of fins306can be disposed along the second portion296. As shown, at least a portion of each of the fins can extend distally from the second distal portion to a distal end of the stemless humeral anchor. The fins306can be spaced circumferentially from one another. In addition, a plurality of second fins307can be disposed at the second end208. The fins306,307can serve to secure the anchor108to the bone tissue and to prevent rotation of the anchor108. As shown inFIG.7C, the second end208of the anchor108may be closed in some embodiments. Furthermore, inFIG.7D, the interior surface212can comprise the apertures277, the groove300, and the slots264, as explained above. In addition, as with the embodiment ofFIGS.6A-6F, the anchor108can comprise a first recess216and a second recess217distal or below the first recess216. As explained above, the first recess216can be sized and shaped to receive an insert161. The second recess217can be sized and shaped to receive a portion of a coupler168for converting the reverse anatomical device ofFIG.7Bto the anatomical device ofFIG.7A. The portions292,296may taper inwardly, such that the second end208is narrower than the first end204. As compared with the anchor104, however, the second end208of the anchor108may be larger than the second end208of the anchor104.

Turning toFIGS.7F-7G, one embodiment of a stemmed humeral anchor112is illustrated. The stemmed humeral anchor112ofFIGS.7F-7Gmay be the same as the stemmed humeral anchor112ofFIG.2A.FIG.7Fis a front perspective view of the stemmed humeral anchor112, according to one embodiment.FIG.7Gis a rear perspective view of the stemmed humeral anchor112ofFIG.7F. The components of the stemmed humeral anchor112can be the same as or generally similar to the anchor112shown inFIG.2A, with the components appended with the letter “A.” As withFIG.2A, the metaphysis portion120of the anchor112can have interior and exterior surfaces212,114that are generally similar to the interior and exterior surfaces212,114of the anchor108illustrated inFIG.7Dand described and illustrated above, which can enable both stemmed and stemless solutions for the kit100. Thus, because the interior and exterior surfaces212,114of the metaphysis portion120of the stemmed humeral anchor112ofFIGS.7F-7Gmay be similar to the surfaces of the anchor108C shown inFIGS.5A-5B, the inserts161shown inFIG.2Acan be inserted to provide a full arthroplasty system for both reverse and anatomical shoulder replacement procedures, and for both stemless and stemmed reconstructions. For example, both the anatomic articular component160and the reverse articular component180ofFIG.2Acan be inserted into the diaphysis portion120of the stemmed humeral anchor112ofFIGS.7F-7G.

With respect to the anatomical stemmed device ofFIG.7F, the coupler168can comprise a bi-surface (e.g., a bi-cone) adaptor having a middle portion162and opposing portions or extensions163A,163B extending from opposite sides of the middle portion162. The proximal extension163A can be configured to connect to the articular body164. The distal extension163B can be configured to be inserted into the second recess217of the metaphysis portion120A. The middle portion162can be received within the first recess216. Further details of the coupler168and other variations of couplers including couplers with expandable disc portions for engaging the surface of the stemmed anchor112about the first recess216are set forth in U.S. Provisional Patent Application No. 62/740,342, filed on Oct. 2, 2018, entitled “MODULAR HUMERAL HEAD,” which is incorporated by reference herein in its entirety.

As shown inFIG.7G, for the reverse anatomical component180, the locking device188, which may comprise a snap ring183in some embodiments, can be received within the groove300to secure at least a portion of the component180within the first recess216. Although the reverse and anatomical components160,180ofFIGS.7F and7Gare illustrated with respect to the stemmed anchor112, it should be appreciated that, as explained above, the same reverse and anatomical components160,180can be used with the stemless anchors104,108.

III. Shoulder Arthroplasty Methods and Instrumentation

The stemless humeral anchors104,108,108B,108C described herein are configured to be able to receive a portion of an articular component160,180below a humeral resection surface RS. As well, the anchors described herein are configured to allow a surgeon to reverse the articular surfaces of the shoulder while accommodating soft tissue of a wide variety of patients. As discussed elsewhere herein, the humeral anchors104,108108B,108C enable a surgeon to adapt a patient or a surgical plan from a stemless anchor to a stemmed anchor. The stemmed anchor can be adapted to occupy the same or a larger volume of the cancellous bone beneath the resection surface RS. Although the methods below are discussed in connection with the humerus H, the anchors and the couplers described herein can 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.

FIG.8Aillustrates a method800for performing a shoulder arthroplasty using the bowl-shaped stemless anchor104with finned distal portion described herein in conjunction with the anatomical articular component160described herein. The method800can include a step801of resecting a humerus H at a superior or proximal end thereof. The resection can be performed with a surgical guide811to create a generally planar surface through the humerus H. The guide811can be a generic guide that is supported on a side surface of the humerus H with rigid pins or bone screws. The guide811can be a patient specific guide, e.g., any of the patient specific guides disclosed in International Patent Application No. PCT/US2018/041531, which is hereby incorporated by reference herein in its entirety. In a step802, the resected surface RS can be protected with a plate member812. The surgeon may be provided with one or more sizing disks813to determine a size of the metaphysis in a step803. The sizing disks813can be configured to facilitate visualization of the space between the implant to be implanted and the cortical boundary of the bone.

The sizing disk813can also have features that aid in referencing the diaphysis of the humerus H, e.g., one or more apertures for guide pins that assure that the reamed surface (see step804) in the metaphysis is properly positioned. This is particularly useful if the stemmed anchor112is used. Further details of sizing disks813and related components to prepare the metaphysis with reference to the diaphysis are discussed in U.S. Provisional Patent Application No. 62/740,257, filed on Oct. 2, 2018, entitled “METAPHYSEAL REFERENCING TECHNIQUE AND INSTRUMENT,” which is hereby incorporated by reference herein in its entirety.

In a step804, the method800can include selecting an appropriately sized reamer814for the resected humerus H. As illustrated inFIG.8A, the reamer814is configured to produce a generally concave recessed surface S in the resected humerus H. For example, in some embodiments, the size of the reamer814can be selected to correspond to the width of the anchor104at or near the first end204, such that the surface S can accommodate the widest portion of the anchor104.

The reamer814is guided over a guidewire819. The guidewire819can be placed by any suitable technique. As noted above, the sizing disk813can be used to assure that the guidewire819is in the correct position. The resection guide811can include or be coupled with a guide device for controlling placement of the guidewire819. This is discussed in International Patent Application No. PCT/US2018/041531, which is incorporated by reference herein.

The method800can proceed to a step805in which a distal opening DO is drilled using an appropriate drilling tool815. The distal opening DO can be sized and shaped to receive the second end208of the anchor104, which may be smaller than the first end204. In a step806, the distal opening DO can be further prepared, e.g., blazed with an appropriate blazing tool816. In one form, blazing involves forming radial channels that are configured to receive the fins306that extent outwardly from the anchor104. The blazing can be performed only below the first recess216to form channels disposed below the first recess216in order to accommodate the fin306. In a step807, the exposed surface(s) of the humerus H can be planarized with a planarizing tool817. After reaming, an appropriately-sized anchor104can be selected for insertion into the prepared resected surface RS of the humerus H. Moving to a step808, components of the anchor or articular body can be inserted into the resected opening(s) of the humerus H in a trial step.

If the sizing in the trial step is suitable or after the proper size has been determined, in a step809, the proper size anchor104can be inserted into the humerus H using a humeral anchor insertion instrument900(see alsoFIGS.9A-10D). As explained herein, the anchor104can be pushed directly into the humerus H with a non-rotational motion of the anchor104, e.g., such that the anchor does not rotate relative to the humerus H as it is being inserted. This has several benefits. The bone below the resection surface RS is not milled or is only minimally disrupted by the process of inserting the anchor104. This is consistent with preserving bone stock for future procedures.

In a step810, the anatomical articular component160can be impacted onto the anchor104. An impactor818can be configured to engage the coupler168and the articular body160with the inserted anchor104. The coupler can be any suitable coupler. As discussed herein, as the inserted anchor104has a receiving portion that is below the resected surface RS of the resected humerus, the impactor818can impact the articular component160such that the articular body164is flush against the resected surface RS of the resected humerus. Further details of the coupler168and variations thereof are discussed in U.S. Provisional Patent Application No. 62/740,342, filed on Oct. 2, 2018, entitled “MODULAR HUMERAL HEAD,” which is incorporated by reference herein in its entirety.

FIG.8Billustrates a method850for performing a shoulder arthroplasty using the bowl-shaped stemless anchor108described herein in conjunction with the reverse anatomical articular component180described herein. Steps801,802, and803may be the same as or generally similar to like-numbered steps inFIG.8A. In step851, however, the reamer814A may be selected to create a distal opening DO so as to accommodate the bowl-shaped structure of the second end208of the anchor108.

A convenient reaming step can be employed in which the reamer814A is a two stage reamer.FIG.8Cis a schematic perspective view of the two-stage reamer814A attached to a shaft820, which the clinician can manipulate to engage the humerus H with the reamer814A, according to some embodiments. The reamer814A can be guided by a humeral guide826, as shown. The guide826can include a portion826A configured to be pinned to a side surface of the humerus H and a removable portion826B configured to guide the reamer shaft820along an outside surface of the shaft thereof. The guide826can be patient specific in one or more aspects. Further details of embodiments of the guide826are set forth in International Patent Application No. PCT/US2018/041531, which is hereby incorporated by reference herein for all purposes. The guide826can be patient specific.FIG.8Dis a schematic perspective front view of the reamer814A.FIG.8Eis a schematic perspective rear view of the reamer814A. The two stage reamer814A can include a proximal body821and a distal body822formed with or coupled to the proximal body821. A first plurality of cutting elements824can extend radially outward from the distal body822. A second plurality of cutting elements823can extend radially outward from the proximal body821. A guidewire lumen825can be provided through the reamer814A, and can be sized and shaped to receive the guidewire819described above.

As shown inFIGS.8D-8E, a lateral dimension (e.g., width, diameter, etc.) of the proximal body821can be larger than a lateral dimension of the distal body822. For example, as shown inFIGS.8D-8E, the proximal body821can be wider than the distal body822. The two-stage reamer can be used to define two differently sized openings in the humerus H, for example, to accommodate the varying diameter of the anchor108. For example, in some embodiments, the distal body822can be configured to create the distal opening DO which receives the finned second portion296of the anchor108. The larger proximal body821can be configured to create a larger proximal opening PO which receives the first portion292of the anchor108.

In step852, the humeral anchor insertion instrument900(which may be the same as or different from the instrument900shown inFIG.8A) may be used to insert an appropriately-sized anchor108into the resection surface RS of the humerus H. As inFIG.8A, in a step853sizers can be used to test the fit of the anchor108into the humerus H. In a step854, an impactor818A can be used to press the reverse articular component180onto the anchor108.

FIGS.9A-9Gillustrate an embodiment of a humeral anchor insertion instrument900comprising an expansion disc906. The instrument900can be configured to reduce or eliminate torque applied to the humeral anchor upon release of the instrument from the anchor.FIG.9Ais schematic cross-sectional view of a portion of the humeral anchor insertion instrument900, according to one embodiment.FIG.9Bis a schematic perspective view of the instrument900ofFIG.9A.FIG.9Cis an enlarged, schematic perspective view of a distal portion of the instrument900ofFIG.9B.FIG.9Dis a schematic top perspective view of a faceplate909for engaging a top, proximal or medial side of the anchor108C.FIG.9Eis a bottom perspective view of the faceplate909ofFIG.9D.FIG.9Fis a schematic side view of the faceplate909.FIG.9Gis a top plan view of an expansion disc906of the instrument900.

As explained in connection withFIGS.8A-8B, the stemless humeral anchors described herein can be inserted into the humerus H with an insertion motion that does not rotate the humeral anchor. It can be important to provide a secure grip on the humeral anchor during insertion, while ensuring that the anchor can be easily released after insertion without the need for applying excessive torque or other forces. Accordingly, the embodiment ofFIGS.9A-9Gprovide improved instrumentation for inserting humeral anchors into the anatomy and for removing the instrumentation from the anchor after insertion. In the illustrated embodiment, the bowl-shaped anchor108B is shown in an example insertion configuration, but it should be appreciated that the instrument900can be used in conjunction with any of the humeral anchors disclosed herein.

Turning toFIGS.9A-9C, the instrument900can comprise a handle901that the clinician can grip during insertion and/or release. A rod903can be disposed within a lumen of the handle901and can be translate and rotate relative to the handle901. The rod903can be coupled to or formed with a grip902. The clinician can rotate the grip902to impart rotation to the rod903. As shown inFIG.9A, a distal portion of the rod903can comprise a tubular threaded portion904having internal threads916B. The handle901can have a distal portion with external threads910A configured to threadably engage with corresponding internal threads910B of the faceplate909to mechanically connect the faceplate909and the handle901.

As shown inFIGS.9D-9F, the faceplate909can comprise a central aperture911and a cavity912sized and shaped to receive the outer dimensions of the handle901. A bolt905can extend through the central aperture911of the faceplate909and into the threaded portion904of the rod903. Outer threads916A of the bolt905can threadably engage with inner threads916B of the threaded portion904of the rod903. As shown inFIG.9A, the distal end of the handle901can bear against the upper surface of the faceplate909.

As shown inFIGS.9A and9G, the instrument900can further comprise an expansion disc906configured to expand radially outward and contract radially inward along a radial direction r. The expansion disc906can comprise a central opening915, a slot914that passes through the central opening915and defines an outer gap in the disc906, and a thinned torsional spring section913. As shown inFIG.9A, the bolt905can further pass through the central opening915of the expansion disc906. A head907of the bolt905can bear against the distal or back surface of the expansion disc906. Furthermore, the faceplate909can comprise one or a plurality of lugs908extending distally from the faceplate909. The lugs908can comprise a thinned portion extending from the faceplate and a wider head at the distal end of the lugs908. The lugs908can extend through the slot914of the expansion disc906with the wider head engaging the back side of the expansion disc906.

The expansion disc906can be configured to engage the interior surface212B of the humeral anchor108B to apply a radially outward gripping force when expanded in a first configuration of the instrument900and to disengage from and to not apply a radially outward force on the interior surface212B of the humeral anchor108B when in a relaxed or contracted state in a second configuration of the instrument900. For example, when the anchor108B is to be inserted into the humerus H, the clinician can rotate the grip902to impart rotation to the rod903. Rotation of the rod903can in turn threadably engage with the bolt905to draw the head907of the bolt905proximally. Proximal movement of the bolt905can cause the head907to bear against the opening915to enlargen the slot914. The thinned torsional hinge portion913can enable a reduced torque to cause expansion. An outermost edge917of the expansion disc906can engage with the groove300B of the anchor108B when the expansion disc906is suitably expanded in a radially outward direction.

The clinician can insert the anchor108B with a non-rotational insertion motion of the anchor. Once the anchor108B is secured to the humerus H, the clinician can release the anchor108B to remove the instrument by rotating the grip902in an opposite direction from what was used during insertion. Such a rotational motion can unthread the bolt905from the threaded portion904of the rod903to cause the bolt905to move distally. Distal movement of the bolt905can cause the expansion disc906to relax and the outermost edge917to move radially inward from the groove300B. Once the outermost edge917is outside the groove300B, the instrument900can be removed proximally.

FIGS.10A-10Dillustrate another embodiment of a humeral anchor insertion instrument900A configured to reduce or eliminate torque applied to the humeral anchor108B upon release of the instrument900A from the anchor108B. AlthoughFIGS.10A-10Dare illustrated in conjunction with the anchor108B, any of the humeral anchors disclosed herein can be used with the instrument900A.FIG.10Ais a schematic perspective side sectional view of the instrument900A.FIG.10Bis an enlarged schematic side sectional view of a distal portion of the instrument900A.FIG.10Cis a side perspective view of a collet925of the instrument900A.FIG.10Dis a bottom perspective view of the collet925ofFIG.10C. Unless otherwise noted, reference numerals inFIGS.10A-10Dmay represent components that are the same as or similar to like-numbered components ofFIGS.9A-9G, with the reference numerals appended with the letter “A.”

For example, as with the embodiment ofFIGS.9A-9G, the instrument900A can comprise a handle901, a rod903A disposed in the handle901, and a grip902A configured to impart rotation to the rod903A. As shown inFIG.10B, however, a distal portion of the rod903A can comprise outer threads916A configured to engage inner threads916B of the collet925. As shown inFIGS.10B-10D, the collet925can comprise a wider proximal portion927and a narrower distal portion926formed with or coupled to the proximal portion927. The collet925can comprise an opening928sized and shaped to receive the distal portion of the rod903A. Further, one or more slots929can extend in a cross-wise pattern through the distal portion926and can intersect with the opening928. Further, one or more anti-rotation recesses930can engage with corresponding features on the anchor108B to limit rotation.

The collet925can be configured to engage an interior surface212B of the humeral anchor108B to apply a radially outward gripping force when expanded in a first configuration of the instrument900A and to disengage from and to not apply a radially outward force on the interior surface212of the humeral anchor108B when in a relaxed or contracted state in a second configuration of the instrument900A. For example, as explained above, it can be important to securely engage the anchor108B during insertion of the anchor108B into the humerus H and to provide an easy release of the instrument900A from the anchor108B after insertion. During insertion, the clinician can rotate the grip902A in a first direction to threadably engage the rod903A with the threaded portion of the collet925. Distal motion of a tapered surface931of the distal end of the rod903A can engage the opening928and slots929to cause the collet925to expand radially outward. Radial outward expansion of the collet925can cause an outermost edge933of the distal portion926of the collet925to be disposed within the groove300B. The clinician can insert the anchor108B into the humerus H with a non-rotatable insertion motion.

After inserting the anchor108B into the humerus H, the clinician can release the instrument900A from the anchor108B by rotating the grip902in a second direction opposite the first used during insertion. Proximal movement of the rod903A can retract the tapered surface931through the opening928, causing the collet925to relax and contract radially. Once the outermost edge933is removed from the groove300B, the clinician can remove the instrument900A with proximal movement.

IV. Manufacturing Methods for Humeral Anchors

FIGS.11A-11Cillustrate various components for improving the throughput and quality of manufacturing for the stemless humeral anchors disclosed herein.

The humeral anchors described herein can be manufactured in any suitable way. For example, various additive manufacturing techniques, such as three-dimensional (3D) printing, can be very effective at manufacturing complex three-dimensional shapes, including shapes with cavities, grooves, rounded or angled surfaces, etc. However, the throughput of additive manufacturing techniques is generally quite low. Accordingly, it can be desirable to utilize high quality, high throughput manufacturing techniques for the humeral anchors disclosed herein. Also, 3D printing may not yield a final article with suitable final dimensions, surface finish or other mechanical properties. As such, other manufacturing processes may be combined with 3D printing to obtain a final, finished article. It should be appreciated thatFIGS.11A-11Care illustrated in connection with the manufacture of an anchor108B, but the techniques and devices disclosed inFIGS.11A-11Bcan be used for any of the stemless humeral anchors disclosed herein.

FIG.11Ais a schematic perspective view of a blank die1001supporting a blank component1010prior to a machining process.FIG.11Bis a schematic side sectional view of the blank die1001ofFIG.11A.FIG.11Cis a schematic perspective view of a finished stemless humeral anchor108B. The die1001shown inFIGS.11A-11Bcan have an external surface1014sized and shaped to have the general contours and tapered surfaces corresponding to complementary interior surfaces212B of the anchor108B. For example, the external surface1014can include an upper tapered portion and a lower tapered portion that may correspond to the inner tapers of the anchor108B as described herein. To accommodate accurate and repeatable manufacturing, the blank die1001can be formed using an additive manufacturing technique, such as 3D printing.

In one variation the blank die1001and the blank component1010are both produced in the same additive manufacturing process from an initial layer, e.g., at an outer or proximal end (to the left inFIG.11A), by adding layers toward the distal end (to the right inFIG.11A). As the layers are formed on top of the prior layer the die1001and the blank component1010are formed together.

The blank die1001can have a notch1002at an outer portion of the blank die1001so that a manufacturing system (e.g., a computer numerical control, or CNC, machine) can automatically detect the orientation of the blank die1001and the blank component1010provided over the external surface1014of the blank die1001. The notch1002also provides an engagement or gripping portion for securing the blank die1001in a machining apparatus. The blank die1001can comprise a central channel1003formed along a length of the die1001and defined by an inner wall1012of the blank die1001. The notch1002can be formed in a first handle portion1006at the outer end. A second handle portion1006′ can be provided at the inner or distal end to improve manipulation of the die1001during machining. An anti-rotation feature1005can be provided at an inner or distal portion of the handle portion1006′ to limit rotation of the die during machining. The anti-rotation feature1005and the notch1002can enable the blank die1001to be securely held during manufacturing.

A CNC machine or other automated manufacturing system can be activated to pattern or connect components onto the exterior surface214B of the anchor108B. The use of the blank die1001can cause the blank component1010to conform to the general geometry of the anchor108B to enable the anchor to be finished without significant additional processing of the exterior surface.FIG.11Cillustrates the final anchor108B produced using the machining techniques disclosed herein.

In one technique, the blank die1001is formed using additive manufacturing. The blank die1001is formed such that the external surface1014approximates the final exterior surface of the anchor108B. In certain techniques, the external surface1014is finished, e.g., using turning, milling or lathing. The notch1002and the anti-rotation feature1005facilitate securing the blank die1001in a machining apparatus, e.g. a turning, milling, lathing process, or other similar process. The first and second handle portions1006,1006′ can be removed after the external surface1014has been prepared. The central channel1003can be formed to have generally the same shape and size as the internal surface of the anchor108B.FIG.11Bshows that the central channel1003may not have the groove300B or slots264B discussed above. These and other features of the interior surface212B can be formed in a subsequent machining process.

As discussed above, the anchor108C has a solid wall311enclosing a distal end of the cavity217C. The anchor108C (and the anchor108) advantageously are enclosed at the solid wall311such that bone matter will be excluded from the interior of the anchor108C as it is inserted into the humerus bone. The die blank1001and the blank component1010can comprise a pre-formed article for the anchor108C (and the anchor108) by forming a solid transverse wall at or near to the junction of the surface1014and the handle1006′. When the handle1006′ is removed, the solid wall311can be provided at the inner or distal end of the blank component1010. The solid wall311can be perforated in some cases while generally enclosing the distal end of the cavity of the anchor108C (or the anchor108). For stemless anchors (such as the anchors108,108C,104) that include the solid wall311to enclose the anchors, the transverse wall at the junction of the surface1014and the handle1006′ can be used to define the solid wall311, and the anchor can be built up layer-by-layer as described above. Once the exterior surfaces214of the anchor are formed, finishing processes can be used but the porous regions and struts and other non-porous regions are formed by a 3D printing process. For stemmed designs, the blank die1001can include an elongate stem-shaped profile and, as with the stemless anchors, the stem can be formed along the elongate stem-shaped profile of the blank die1001. Still other methods of forming the stemmed anchor may be suitable.

These methods are applicable to the stemless anchors described herein. The approaches apply most directly to the components described herein that are at least partially rotationally symmetric.

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 “coupling a glenoid guide with the glenoid rim” include “instructing coupling of a glenoid guide with a glenoid rim.”