US20130123929A1 - Convertible glenoid implant - Google Patents

Abstract

A shoulder implant assembly constructed in accordance to one example of the present disclosure includes a frame member, a cup, and a glenosphere. The frame member can have a central hub and a first arm extending therefrom. The frame member can be configured to selectively and alternatively couple with first shoulder implant components in a traditional shoulder configuration and with second shoulder implant components in a reverse shoulder configuration. The cup can have a concave surface that is configured to articulate with a humeral head component. The cup can be selectively coupled to the frame member in the traditional shoulder configuration. The glenosphere can have an outer articulating surface that is configured to articulate with a second cup. The glenosphere can be selectively coupled to the frame member in the reverse shoulder configuration.

Description

FIELD
• The present disclosure relates to a shoulder implant assembly and a related method for converting a traditional shoulder implant to a reverse shoulder implant.
BACKGROUND
• This section provides background information related to the present disclosure which is not necessarily prior art.
• A natural shoulder joint may undergo degenerative changes due to a variety of etiologies. When these degenerative changes become so far advanced and irreversible, it may ultimately become necessary to replace a natural shoulder joint with a prosthetic shoulder joint. When implantation of such a shoulder joint prosthesis becomes necessary, the natural head portion of the humerus may be resected and a cavity may be created in the intramedullary canal of the host humerus for accepting a humeral component. The humeral component may include a head portion used to replace the natural head of the humerus. Once the humeral component has been implanted, the glenoid cavity positioned at the glenoid may also be resurfaced and shaped to accept a glenoid component. The glenoid component generally includes an articulating surface which is engaged by the head portion of the humeral component. Such an implant configuration is generally referred to as a traditional shoulder configuration. In some instances, it may be necessary to convert the traditional shoulder configuration into a reverse shoulder configuration such as to achieve a higher level of constraint. In this regard, the humeral component and glenoid component may need to be removed and replaced with reverse shoulder components. When converting a traditional shoulder configuration to a reverse shoulder configuration, it is desirable to provide an efficient and minimally invasive transition on both the humeral side of the system and the glenoid side of the system.
SUMMARY
• This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.
• A shoulder implant assembly constructed in accordance to one example of the present disclosure includes a frame member, a first cup, and a glenosphere. The frame member can have a central hub and a first arm extending therefrom. The frame member can be configured to selectively and alternatively couple with first shoulder implant components in a traditional shoulder configuration and with second shoulder implant components in a reverse shoulder configuration. The first cup can have a concave surface that is configured to articulate with a humeral head component. The first cup can be selectively coupled to the frame member in the traditional shoulder configuration. The glenosphere can have an outer articulating surface that is configured to articulate with a second cup. The glenosphere can be selectively coupled to the frame member in the reverse shoulder configuration.
• According to additional features, the shoulder implant assembly can further include a first peg configured to mate with the first arm of the frame member in the traditional shoulder configuration. The first peg can have an elongated body that extends a first distance. A first bone screw can be configured to mate with the first arm of the frame member in the reverse shoulder configuration. The first bone screw can have an elongated body that extends a second distance. The second distance can be greater than the first distance. The first arm can define a first receiving portion configured to selectively and alternatively receive the first peg in the traditional shoulder configuration and the first bone screw in the reverse shoulder configuration. The first receiving portion can include a first boss defining a first threaded aperture.
• According to additional features, the first peg and the first bone screw can have threads formed thereon configured to threadably mate with the threaded aperture. The shoulder implant assembly can further comprise an adapter having a male tapered outer surface that is configured to be received into a complementary female tapered surface defined on the glenosphere. The adapter can define a throughbore configured to receive a central bone screw extending through the central hub in the reverse shoulder configuration. In one configuration, the first arm can be porous coated.
• According to other features, the frame member can further include a second arm and a third arm that extend from the central hub. The first, second, and third arms can each include a receiving portion having a hub configured to selectively and alternatively receive a peg in the traditional shoulder configuration and a bone screw in the reverse shoulder configuration. The peg and the bone screw can have distinct lengths. In one configuration, the first, second, and third arms extend in a Y-shaped pattern.
• A method of performing shoulder arthroplasty according to one example of the present teachings can include implanting a frame member into a glenoid. A first cup can be coupled to the frame member. The first cup can have a first concave articulating surface. A humeral component having a humeral head can be implanted into a humerus. The humeral head can be configured to articulate relative to the first concave articulating surface. The cup can be removed from the frame member subsequent to bone interdigitation with the frame member while leaving the frame member implanted in the glenoid. A glenosphere can be coupled to the frame member. The humeral head can be removed from the humeral component. A second cup can be coupled to the humeral component. The second cup can have a second concave articulating surface. The glenosphere can be configured to articulate relative to the second concave articulating surface.
• According to additional features, the method can further comprise advancing a peg through a boss formed on an arm extending from a central hub of the frame member and into the glenoid. Coupling the glenosphere can include removing the peg from the boss and subsequently inserting a bone screw through the boss. The bone screw can penetrate into the glenoid a further distance as compared to the peg. The method can further include advancing a central peg through the central hub and into the glenoid. The central peg can be removed. An adapter can be coupled to the glenosphere. A central bone screw can be inserted through the adapter and into the glenoid.
• Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
DRAWINGS
• The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.
• FIG. 1 is a front perspective view of a frame member constructed in accordance to one example of the present teachings and shown adjacent a right glenoid cavity;
• FIG. 2 is an exploded side view of the frame member ofFIG. 1 and shown as part of a traditional shoulder implant assembly including a series of pegs configured to couple with a first cup according to one configuration;
• FIG. 3 is a side view of the frame member ofFIG. 1 shown implanted as part of a traditional shoulder implant assembly;
• FIG. 4 is an exploded perspective view of the frame member shown as part of a reverse shoulder implant assembly including an adapter, a series of bone screws, and a glenosphere according to one example;
• FIG. 5 is a partial exploded perspective view of the traditional shoulder implant assembly being removed from the glenoid while leaving the frame member implanted;
• FIG. 6 is an exploded perspective view of the glenosphere and adapter ofFIG. 4 aligned for coupling to the frame member;
• FIG. 7 is a side view of the glenosphere coupled relative to the frame member in the reverse shoulder configuration; and
• FIG. 8 is a side view of the reverse shoulder implant assembly shown in an implanted position.
• Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.
DETAILED DESCRIPTION
• Example embodiments will now be described more fully with reference to the accompanying drawings.
• With initial reference now toFIGS. 1,3, and8, a frame member constructed in accordance to one example of the present teachings is shown and generally identified atreference numeral10. As will become appreciated from the following discussion, theframe member10 is configured to be implanted into aglenoid cavity12 of ascapula14 as part of either a traditional shoulder implant assembly20 (FIG. 3) or a reverse shoulder implant assembly22 (FIG. 8). More particularly, theframe member10 is configured to be implanted into theglenoid cavity12 as part of a traditional shoulder implant assembly and remain implanted in theglenoid cavity12 as part of a reverse shoulder implant assembly. In this regard, theframe member10 can remain implanted and relatively undisturbed during a transition from converting a traditional shoulder implant into a reverse shoulder implant as will become appreciated from the following discussion.
• With particular reference now toFIGS. 1 and 2, theframe member10 will be described in greater detail. Theframe member10 generally includes acentral hub28 having afirst arm30, asecond arm32, and athird arm34 extending therefrom. Thefirst arm30 includes afirst boss36 formed on a terminal end thereof. Thesecond arm32 includes asecond boss38 formed on a terminal end thereof. Thethird arm34 includes athird boss40 formed on a terminal end thereof. The first, second, andthird bosses36,38, and40 provide first, second, and third receivingportions42,44, and46, respectively. The first receivingportion42 has afirst bore50 defined through thefirst boss36. Thesecond receiving portion44 has asecond bore52 defined through thesecond boss38. Thethird receiving portion46 defines athird bore54 defined through thethird boss40. Thecentral hub28 defines acentral bore58. Theframe member10 can be formed of biocompatible material such as titanium for example.
• Thefirst boss36 can includefirst threads60. Thesecond boss38 can includesecond threads62 thereon. Thethird boss40 can includethird threads64 thereon. Thecentral hub28 can havecentral threads68 formed thereon. The first, second, andthird arms30,32, and34 can be formed of porous material or have porous material disposed thereon.
• Turning now toFIG. 3 with continued reference toFIG. 2, the traditionalshoulder implant assembly20 will be further described. The traditionalshoulder implant assembly20 generally includes theframe member10, afirst cup70, ahumeral head72, anadapter74, ahumeral stem76, and a collection offirst fasteners78. Thefirst cup70 generally includes acup body80 that defines a concave articulatingsurface82. Thecup body80 can have afirst leg84, asecond leg86, and a third leg (not specifically shown). Thefirst leg84 can include a distal connectingend90 extending from apost92. Thesecond leg86 can have a distal connectingend94 extending from apost96. Acentral leg100 having a distal connectingend102 extending from apeg104.
• Thehumeral head72 has an articulatingsurface110 that is configured to articulate relative to the concave articulatingsurface82 of thefirst cup70. Thehumeral head72 can further include a female tapered receivingportion112. Thehumeral stem76 can define a female tapered receivingportion114. Theadapter74 generally includes a firstmale taper120 and a secondmale taper122. The first and second male tapers120 and122 are each generally cylindrical. The firstmale taper120 can have a larger diameter than the secondmale taper122. The firstmale taper120 can be angled to cooperate with the corresponding female tapered receivingportion112 of thehumeral head72. The secondmale taper122 is angled to cooperate with the female tapered receivingportion114 of thehumeral stem76. In one example, the respective first and second male tapers120 and122 can create a Morse taper lock with the complementary female tapered receivingportions112 and114, respectively.
• Thefirst fasteners78 can generally include afirst peg130, asecond peg132, acentral peg133, and a third peg (not specifically shown). Thefirst peg130 includes afirst head134 and a pair ofradial flanges135 extending from alongitudinal shaft136. Thefirst head134 can includethreads140 formed thereon. Thesecond peg132 can include asecond head142 and a pair ofradial flanges144 that extend from ashaft146. Thesecond head142 can includethreads150 thereon. Thecentral peg133 generally includes ahead160 and a series ofradial flanges162 that extend from anelongated shaft164. Thehead160 can includethreads170 thereon. Thefirst fastener78 can be formed of ultra high molecular weight polyethylene (UHMWPE) or other suitable material. It is further appreciated that the particular geometry and configurations of the pegs is merely exemplary and other fasteners such as bone screws may be used.
• With reference now toFIGS. 4 and 8, the reverseshoulder implant assembly22 will be further described. The reverseshoulder implant assembly22 can generally include theframe member10, aglenosphere180, asecond cup182, thehumeral stem76, anadapter186, and a series ofsecond fasteners190. Theglenosphere180 generally includes abody192 having an outer articulatingsurface194 and defines a female tapered receivingportion196. Thesecond cup182 can include asecond cup body200 that includes a male taperedportion202 configured to cooperatively mate with the female tapered receivingportion114 of thehumeral stem76. Thesecond body200 of thesecond cup182 further includes a concave articulatingsurface206 that is configured to articulate with the outer articulatingsurface194 of theglenosphere180. Theadapter186 generally includes anadapter body212 having an outertapered surface214. Theadapter186 defines athroughbore220.
• Thesecond fasteners190 can generally include afirst bone screw230, asecond bone screw232, a third bone screw (not specifically shown), and acentral bone screw236. Thefirst bone screw230 can include a threadedhead240 and a threadedshank242. Thesecond bone screw232 can include a threadedhead244 and a threadedshank246. Thecentral bone screw236 can include atapered head250 and threadedshank252. Thesecond fasteners190 are merely exemplary. It will be appreciated that other fasteners may be used. In the present example, thesecond fasteners190 are longer in axial length than thefirst fasteners78 to penetrate deeper into the bone of theglenoid cavity12.
• One method of implanting the traditionalshoulder implant assembly20 according to one example of the present teachings will now be described. Once theglenoid cavity12 has been sufficiently reamed, a surgeon can prepare acentral bore270, afirst hole272, asecond hole274, and athird hole276 into the glenoid cavity12 (FIG. 1). It will be appreciated that the first, second, andthird bores50,52, and54 may be used as a reference in determining the location of therespective holes272,274, and276. Next, theframe member10 can be positioned onto theglenoid cavity12 and thefirst peg130,second peg132 and third peg (not shown) can be inserted into thefirst bore50, second bore52 andthird bore54, respectively of theframe member10. In this regard,respective flanges135 and144 as well as the flanges from the third peg (not shown) are inserted into the bone of theglenoid cavity12. At this point, thecentral peg133 can be located into thecentral bore58. Theradial flanges162 can be caused to be inserted into the bone of theglenoid cavity12. Thefirst cup70 can then be located into the first, second, and third receivingportions42,44, and46. Specifically, the respective distal connecting ends90 and94 of thelegs84 and86 can be located partially into the respective first andsecond bores50 and52 via snap-fit or other means. The third connecting end from the third peg (not shown) may also concurrently be located partially into thethird bore54. Thehumeral head72 can then be coupled to thehumeral stem76 by way of theadapter74.
• As identified above, in some examples, it may become necessary to convert the traditional shoulder implant assembly20 (FIG. 3) into the reverse shoulder implant assembly22 (FIG. 8). According to the present disclosure, theframe member10 can remain implanted into theglenoid cavity12 during the conversion from the traditionalshoulder implant assembly20 to the reverseshoulder implant assembly22. In this regard, theframe member10 can take advantage of any bone that has interdigitated into the porous surface of the respective first, second, andthird arms30,32, and34. Moreover, the conversion can be minimally invasive as theframe member10 can remain relatively undisturbed and implanted in the bone of theglenoid cavity12.
• Turning now toFIG. 5, thefirst cup70 and thefirst fasteners78 are then removed from theframe member10. Next, as viewed fromFIGS. 6-8, thefirst bone screw230, thesecond bone screw232, and the third bone screw of thesecond fasteners190 can be driven through the respective first, second, andthird bores50,52, and54. Thecentral bone screw236 can then be inserted into thethroughbore220 of theadapter186 and located into thecentral bore58. The threadedshank252 of thecentral bone screw236 can be driven into the bone of theglenoid cavity12. Thethreads242 and246 of the bone screws230 and232 can likewise be driven into the bone of theglenoid cavity12. Theglenosphere180 can then be located relative to theadapter186. Specifically, thetapered surface214 of theadapter186 can be located into the female tapered receivingportion196 of theglenosphere180. The male taperedportion202 of thesecond cup182 can then be inserted into the female tapered receivingportion114 after thehumeral head72 andadapter74 have been removed from thehumeral stem76.
• The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.
• Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.
• The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed.
• When an element or layer is referred to as being “on,” “engaged to,” “connected to,” or “coupled to” another element or layer, it may be directly on, engaged, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to,” “directly connected to,” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
• Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as “first,” “second,” and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.
• Spatially relative terms, such as “inner,” “outer,” “beneath,” “below,” “lower,” “above,” “upper,” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the example term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

Claims (19)

1. A shoulder implant assembly comprising:

a frame member having a central hub and a first arm extending therefrom, wherein the frame member is a single component that is configured to selectively and alternatively couple with first shoulder implant components in a traditional shoulder configuration and with second shoulder implant components in a reverse shoulder configuration;

a first cup having a concave surface configured to articulate with a humeral head component, wherein the first cup is selectively and directly coupled to the frame member in the traditional shoulder configuration; and

a glenosphere having an outer articulating surface configured to articulate with a second cup, wherein the glenosphere is selectively and directly coupled to the frame member in the reverse shoulder configuration.

2. The shoulder implant assembly ofclaim 1, further comprising:

a first peg configured to mate with the first arm of the frame member in the traditional shoulder configuration, the first peg having an elongated body that extends a first distance; and

a first bone screw configured to mate with the first arm of the frame member in the reverse shoulder configuration, the first bone screw having an elongated body that extends a second distance, wherein the second distance is greater than the first distance.

3. The shoulder implant assembly ofclaim 2 wherein the first arm defines a first receiving portion configured to selectively and alternatively receive the first peg in the traditional shoulder configuration and the first bone screw in the reverse shoulder configuration.

4. The shoulder implant assembly ofclaim 3 wherein the first receiving portion includes a first boss defining a first threaded aperture.

5. The shoulder implant assembly ofclaim 4 wherein the first peg and the first bone screw have threads formed thereon configured to threadably mate with the threaded aperture.

6. The shoulder implant assembly ofclaim 1, further comprising an adapter having a male tapered outer surface configured to be received into a complementary female tapered surface defined on the glenosphere.

7. The shoulder implant assembly ofclaim 6 wherein the adapter defines a throughbore configured to receive a central bone screw extending through the central hub in the reverse shoulder configuration.

8. The shoulder implant assembly ofclaim 1 wherein the first arm is porous coated.

9. The shoulder implant assembly ofclaim 1 wherein the frame member further includes a second arm and a third arm extending from the central hub, wherein the first, second and third arms each include a receiving portion having a hub configured to selectively and alternatively receive a peg in a traditional shoulder configuration and a bone screw in the reverse shoulder configuration, wherein the peg and the bone screw have distinct lengths.

10. The shoulder implant assembly ofclaim 9 wherein the first, second and third arms extend in a Y-shaped pattern.

11. A shoulder implant assembly comprising:

a frame member having first, second and third arms extending outwardly from a central hub, wherein each of the first, second and third arms includes a boss defining a bore, wherein the frame member is a single component that is configured to be implanted into a glenoid and selectively and alternatively couple with first shoulder implant components in a traditional shoulder configuration and with second shoulder implant components in a reverse shoulder configuration;

a first cup having a concave surface configured to articulate with a humeral head component, wherein the first cup is selectively and directly coupled to the frame member in the traditional shoulder configuration;

a glenosphere having an outer articulating surface configured to articulate with a second cup, wherein the glenosphere is selectively and directly coupled to the frame member in the reverse shoulder configuration;

a series of first fasteners each having an elongated body extending a first length between a first end and a second end, the first end configured to be at least partially received by the respective bosses and the second end configured to couple and directly engage the cup in the traditional shoulder configuration; and

a series of second fasteners each having an elongated body extending a second length between a first end and a second end, the first end configured to be at least partially received by the respective bosses in the reverse shoulder configuration, wherein the second length is greater than the first length.

12. The shoulder implant assembly ofclaim 11 wherein the series of first fasteners each have a plurality of radial flanges extending from the elongated body.

13. The shoulder implant assembly ofclaim 11 wherein each of the first fasteners are threaded at the first end and wherein the bore of each respective boss is threaded, wherein the first fasteners are configured to threadably mate with the respective bosses in the traditional shoulder configuration.

14. The shoulder implant assembly ofclaim 11, further comprising an adapter having a male tapered outer surface configured to be received into a complementary female tapered surface defined on the glenosphere.

15. The shoulder implant assembly ofclaim 14 wherein the adapter defines a throughbore configured to receive a central bone screw extending through the central hub in the reverse shoulder configuration.

16. The shoulder implant assembly ofclaim 11 wherein the first, second and third arms are porous coated.

17.-20. (canceled)

21. The shoulder implant assembly ofclaim 1 wherein the first cup has a first distal connecting end extending away from the central hub and that is received and engaged by a receiving portion on the first arm in a snap-fit relationship in the traditional shoulder configuration.

22. The shoulder implant assembly ofclaim 11 wherein the first cup has a first, second and third distal connecting end extending from the central hub, wherein the first, second and third distal connecting ends are received and engaged by a first, second and third receiving portion on the first, second and third arms, respectively in the traditional shoulder configuration.

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