ANCHORING MEMBER FOR A JOINT REPLACEMENT

Abstract

This disclosure relates to an anchoring member for a joint replacement, comprising a proximal interface part and a distal portion, the distal portion being configured to be anchored within bone tissue and the proximal interface part being configured for mounting a joint member of the joint replacement. The proximal interface part comprises a concave interface surface.

Claims

1. An anchoring member for a joint replacement, the anchoring member comprising a proximal interface part and a distal portion, the distal portion being configured to be anchored within bone tissue and the proximal interface part being configured for mounting a joint member of the joint replacement, wherein the proximal interface part comprises a concave interface surface.

2. The anchoring member of claim 1, wherein the concave interface surface is formed as a recess.

3. The anchoring member of claim 2, wherein the concave recess has a curved profile, the curved profile being spherical, ellipsoidal, or ovoid shaped.

4. The anchoring member of claim 1, wherein the anchoring member comprises a mounting hole in the proximal interface part, the mounting hole being disposed in the concave interface surface for fixedly attaching the joint member, the mounting hole comprising a thread for engagement with a fixation member or a tapered portion.

5. The anchoring member of claim 1, wherein the anchoring member comprises a plurality of fins extending in radial directions in relation to a direction of insertion of the anchoring member into the bone.

6. The anchoring member of claim 1, wherein the concave interface surface comprises an indexing structure.

7. The anchoring member of claim 6, wherein the indexing structure comprises at least one indexing recess, the at least one indexing recess being able to mate with a corresponding protrusion of the joint member.

8. The anchoring member of claim 1, the anchoring member further comprising a stem part that is configured to be inserted into the bone, wherein the stem part is modular.

9. A joint member for a joint replacement, the joint member comprising a proximal end and a distal interface part, the proximal end being formed as a joint surface and the distal interface part being configured for mounting an anchoring member of claim 1, wherein the joint surface is a ball joint surface, and wherein the distal interface part comprises a convex interface surface.

10. The joint member of claim 9, wherein the joint member comprises an intermediate component and a joint component, wherein the intermediate component and the joint component are preferably fixedly attached to each other by means of a friction fit or a form fit.

11. The joint member of claim 9, wherein the interface surface of the joint member includes an indexing structure, the indexing structure preferably being a protrusion configured to mate with an indexing recess of an anchoring member.

12. The joint member of claim 9, wherein the joint member is configured as an anatomical or reverse joint member.

13. A joint replacement component, the joint replacement component being for replacing one side of a joint, the joint replacement component comprising: an anchoring member, and a joint member, wherein, in an assembled state, the concave interface surface of the anchoring member and the convex interface surface of the joint member are in surface contact so that the joint member is partly accommodated within the anchoring member.

14. The joint replacement component of claim 13, wherein the joint replacement is a replacement for a shoulder joint.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0076] FIG. 1 shows an anchoring member for a joint replacement according to an embodiment.

[0077] FIGS. 2A, 2B, and 2C show another anchoring member for a joint replacement according to another embodiment.

[0078] FIG. 3 shows, in a side view, an arrangement of a joint replacement component according to an embodiment.

[0079] FIGS. 4A, 4B, and 4C show different views of an embodiment of the distal interface part.

[0080] FIG. 5A shows an embodiment of a modular anchoring portion.

[0081] FIG. 5B shows an embodiment of a proximal part of the anchoring portion.

[0082] FIG. 6 shows exploded views of different embodiments of a reverse joint replacement.

[0083] FIGS. 7A and 7B show an embodiment of an intermediate component.

[0084] FIG. 8 shows an embodiment of a reverse joint component.

[0085] FIGS. 9A and 9B show an embodiment of an intermediate component.

[0086] FIGS. 10A and 10B show an embodiment of a reverse joint component.

[0087] FIG. 11 shows reverse joint components according to further embodiments.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0088] FIG. 1 shows an anchoring member 1 for a joint replacement according to an embodiment.

[0089] The anchoring member 1 has two portions, namely, a proximal interface part 3, and a distal portion 5. The distal portion 5 of the embodiment shown in FIG. 1 has a stem part 15. In this embodiment, stem part 15 has an elongate shape and is configured so as to be insertable into a long bone, for example, into a humerus or a femur, so that the distal portion 5 can be anchored within the bone tissue of such a bone.

[0090] The proximal interface part 3 is configured for mounting a joint member of the joint replacement and comprises a concave interface surface 7. As illustrated, the concave interface surface 7 may be formed as a recess, i. e. as an inwardly bulging indentation. Nonetheless, instead of being formed as a three-dimensional concavity, it may also be formed as a two-dimensional concavity as described above.

[0091] The proximal interface part 3 of the embodiment shown in FIG. 1 further comprises a central hole 18, and a plurality of indexing recesses 20 arranged around the central hole 18. In this embodiment, the indexing recesses 20 are arranged equidistantly on a circle around the central axis of the mounting hole 18. The mounting hole 18 can be provided with a thread (not shown). Alternatively, the mounting hole 18 can be configured as a tapered hole.

[0092] FIG. 1 also shows that the proximal interface part 3 also comprises a mounting hole 18 for receiving a corresponding part of the joint member, the mounting hole 18 being disposed in the concave interface surface 7.

[0093] This mounting hole 18 in the concave interface surface 7 allows for mounting a joint member (such as a joint member 100 to be discussed below) on the anchoring member 1 by inserting the corresponding part of the joint member 100 into the mounting hole 18.

[0094] Preferably the anchoring member 1 and a joint member are attached to each other via a tapered connection. Accordingly and as already described above, the concave interface surface facing proximally and the corresponding convex interface surface of a joint member facing distally are at a distance to each other when being assembled. This prevents a double fit from occurring.

[0095] FIGS. 2A, 2B, and 2C show another anchoring member 50 for a joint replacement according to another embodiment in different views. The embodiment shown in FIGS. 2A, 2B, and 2C shows an anchoring member 50, which similarly to the anchoring member 1 shown in FIG. 1 has two portions, namely a proximal interface part 3 and a distal portion 5.

[0096] The proximal interface part 3 is configured for mounting a joint member of the joint replacement and comprises a concave interface surface 7. Similar to the embodiment shown in FIG. 1, the concave interface surface 7 is also preferably formed as a three-dimensional recess.

[0097] The proximal interface part 3 of the embodiment shown in FIG. 2 further comprises a central hole 18. As illustrated, a plurality of indexing recesses 20 may be arranged equidistantly around the mounting hole 18 (cf. FIG. 1).

[0098] The distal portion 5 of the anchoring member 50 is configured to be inserted into a long bone, such as a humerus. The direction of insertion defines an axis of insertion of the anchoring member 50, which in case of the anchoring member 50 shown in FIG. 2, is the central axis of the mounting hole 18. However, the axis of insertion is not limited to correspond to the axis of the mounting hole 18 but can be different therefrom.

[0099] In the embodiment shown in FIGS. 2A, 2B, and 2C, the distal portion 5 comprises a plurality of fins 16 that extend in radial directions in relation to the insertion direction of the anchoring member 50. The embodiment shown comprises four fins 16, and pairs of two essentially symmetrical fins 16 are arranged opposite to each other with respect to the axis of insertion into the bone. It is to be noted that the number of fins 16 is not limited to four but can be any other number. Moreover, while the fins 16 in the shown anchoring member 50 are essentially equally sized, other embodiments include differently sized fins, like for example a configuration in which one pair of opposing fins is smaller than another pair of opposing fins in the direction of the insertion or the direction radial thereto.

[0100] In comparison to the anchoring member 1 shown in FIG. 1, the embodiment shown in FIG. 2 is only inserted into the cranial portion of the humerus bone.

[0101] FIG. 3 shows, in a side view, an arrangement of a joint replacement component 200 according to an embodiment.

[0102] The joint replacement component 200 comprises an anchoring member, which can be essentially one of the anchoring members 1, 50 described above, and a joint member 100. In the embodiment shown in FIG. 3, the joint member 100 is an anatomical joint member. However, the joint member 100 may also be a reverse joint member.

[0103] In the embodiment shown in FIG. 3, the joint member 100 comprises a joint component 19 with a proximal end 102, which is formed as a joint surface, and an intermediate part 112 comprising a distal interface part 104 with a convex interface surface 108. The distal interface part 104 comprises a convex interface surface 108 and is configured to be mounted to an anchoring member 1, 50 of the joint replacement. The joint surface of the proximal end 102 is formed as a convex ball joint surface. It is to be noted that, however, the proximal end 102 can also be formed as a concave ball joint surface in the case of a reverse joint replacement.

[0104] As shown in the embodiment of FIG. 3, the joint member 100 may be composed of separate parts, such as the intermediate component 112 and the joint component 19 The intermediate component 112 may be fixed to the anchoring member 1, 50 by means of for example fixation member 12, while the joint component 19 may be fixed to the intermediate component 112 by means of a friction fit or other methods known in the art.

[0105] Anchoring member 1, 50 can also be connected to an intermediate component 101 with an offset fixation member 115 and an indexing structure 106.

[0106] It is, however, to be noted that the anchoring members 1, 50 may also be connected to an integrally formed joint member 150.

[0107] FIGS. 4A, 4B, and 4C show different views of an embodiment of the intermediate component 112. The intermediate component 112 comprises a proximal engagement portion 22, which is configured to be engaged with the joint component 19 (not shown in FIG. 4), and a distal interface part 104, which comprises a convex interface surface 108. The distal interface part 104 further comprises a fixation member 14, which in this case is a protrusion that is configured to mate with a corresponding mounting hole 18 of an anchoring member 1, 50 (see description above). That is, the fixation member 14 can have a thread and/or can be tapered in order to engage with the mounting hole 18 by means of a friction fit. Additionally or alternatively, it may be in engagement via a form fit.

[0108] The intermediate component 112 shown in FIGS. 4A, 4B, 4C also comprises a plurality of holes 111 arranged circumferentially and penetrating the distal interface part, which can for example be used as suture holes.

[0109] In case that the intermediate component 112 is connected to the anchoring member 1, 50 by means of a separate fixation member 12, such as a screw or a rivet, the fixation member 14 may be formed so as to center the intermediate component 112 with respect to the mounting hole 18.

[0110] In the embodiment shown in FIG. 4 the fixation member 14 is provided centered on the interface surface 108 of the intermediate component 112. However, it is to be noted that the fixation member 14 can also be disposed offset from the rotational center of the distal interface part 104 such that a rotation about the fixation member can be used to adjust the orientation of the intermediate component 112 with respect to, for example, the mounting hole 18 of an anchoring member 1, 50.

[0111] In addition, there may be provided an indexing structure. More specifically, a protrusion (not shown) next to the fixation member 14 may engage a corresponding indexing recess 20 of an anchoring member 1, 50.

[0112] Preferably, the convex interface surface 108 has a curvature, in particular a radius, that is essentially identical to or smaller than the curvature, in particular radius, of the concave interface surface 7 of an anchoring member 1, 50 to be engaged with the intermediate component 112. In case that the fixation member 14 is configured to form a tapered connection with the mounting hole 18 of the anchoring member 1, 50, the convex interface surface 108 of the intermediate member 112 and the concave interface surface 7 of the anchoring member come close to each other, but do not contact each other, such that the intermediate member 112 can be placed to some extent inside the anchoring member 1, 50, which allows to reduce the space required for the joint replacement component 200. More specifically, the interface surfaces 7, 108 are preferably at a distance to each other such as a distance smaller than 3, 2, or 1 mm. This distance may (also) be caused by the curvature of the convex interface surface 108 being smaller than the curvature of the concave interface surface 7.

[0113] In case that the fixation member 14 is configured to be in a threaded engagement with the mounting hole 18 of the anchoring member 1, 50, the interface surfaces of the anchoring member 1, 50 and the intermediate part 112 may be in contact with each other. Also in this case, the convex and concave shape of the intermediate part 112 and the anchoring member 1, 50, respectively, allow for a reduced volume for the joint replacement component 200.

[0114] FIG. 5A shows an embodiment of a modular anchoring portion 1. In the embodiment shown in FIG. 5A, the anchoring member 1 comprises a proximal interface part 3 and a distal portion 5. The proximal interface part 3 of the embodiment shown in FIG. 5A comprises a concave interface surface 7, preferably formed as a recess, and a central mounting hole 18. Further, the proximal interface part 3 comprises indexing recesses 20 arranged circularly around the mounting hole 18.

[0115] The distal portion 5 of the anchoring member 1 shown in FIG. 5A is configured to be anchored within bone tissue and has a modular configuration. In particular, the modular anchoring portion 1 comprises a proximal part 301, and a distal part 303, which are attached to each other, for example by means of a fastener (not shown).

[0116] The distal part 303 of the embodiment may have a substantially even surface for being cemented or a surface configured for bone ingrowth. The proximal part 301 may have a textured surface for supporting the attachment of soft tissue structures.

[0117] FIG. 5B shows an embodiment of a proximal part 301. In the embodiment shown in FIG. 5B, the surface of proximal part 301 is textured by protrusions 305, which protrude from a part of the outer surface of the proximal part 305. Said protrusions 305 enhance the interaction with surrounding tissue, for example with bone tissue or with soft tissue, and enhances the stability of the anchoring member.

[0118] Proximal part 301 and distal part 303 may be made of different materials.

[0119] FIG. 6 shows exploded views of different embodiments of a reverse joint replacement.

[0120] As illustrated, an anchoring member 1, 50, can be connected to an intermediate component 412, which forms part of a reverse joint member 430 for a reverse joint replacement. For example, the anchoring member 1, 50 can be connected to an intermediate component 412 shown in FIG. 7A and FIG. 7B, which, in turn, can be connected to a reverse joint component 419 shown in FIG. 8. Alternatively, anchoring member 1, 50 can be connected to an inclined intermediate component 512 shown in FIG. 9A and FIG. 9B, which, in turn, can be connected to an inclined reverse joint component 519 shown in FIGS. 10A and 10B.

[0121] Intermediate component 412 has, similar to intermediate component 112, a distal interface part 404 with a convex interface surface 408, on which a fixation member 414 is positioned.

[0122] Intermediate component 412 has a recess 420, which can be configured with a thread or taper in order to fixedly engage with a corresponding protrusion 421 of a joint component 419 for a reverse joint replacement.

[0123] Alternatively, a reverse joint member 530 can be an assembly of an intermediate component 512, as shown in FIGS. 9A and 9B, and a joint component 519, as shown in FIGS. 10A and 10B.

[0124] For a reverse joint replacement, an intermediate component 512 is formed with a recess 520 for engaging with a corresponding protrusion 521 of a joint component 519. The intermediate component 512 can be formed with an inclined rim 515 or mounting plane with respect to the axis of the fixation member 514.

[0125] Additionally, intermediate component 512 is provided with an indexing protrusion 506, which is configured so as to be engageable with the indexing recesses 20 of an anchoring member 1, 50 when the fixation member 14 is in engagement with the mounting hole 18 of the anchoring member 1, 50. This allows for adjusting the direction of inclination of the plane of the intermediate member 512 with respect to the anchoring member 1, 50.

[0126] The joint component 519 shown in FIGS. 10A and 10B is configured with a protrusion 521 to engage with the corresponding recess 520 of the intermediate component 512. The joint component 519 has a proximal end 502 that is formed as a concave joint surface in order to interact with a corresponding convex glenoidal joint member (not shown).

[0127] The joint surface has a rim 525 which is inclined with respect to the axis of the protrusion 521, such that the joint component 519 defines an inclined joint surface.

[0128] The inclination of the joint surface as provided by the inclined intermediate component 512 and the inclined joint component 519 can be selected in accordance with the patient's anatomy as shown in FIG. 11.

In this respect, FIG. 11 shows: [0129] a neutral intermediate component 610, in which the central axis of the fixation member 614 and the axis of the plane 616 are substantially aligned; [0130] a positively inclined intermediate component 620, in which the axis of the plane 626 deviates in a cranial direction from the axis of the fixation member 624; and [0131] a neutral intermediate component 630, in which the central axis of the fixation member 634 and the central axis of the distal interface part 604 are offset.
Further, FIG. 11 illustrates: [0132] neutral joint component 611, in which the cranial plane 618 and the caudal plane 619 are substantially parallel, [0133] a 10° inclined joint component 621, in which the cranial plane 628 and the caudal plane 629 form a 10° angle, and [0134] a 20° inclined joint component 631, in which the cranial plane 638 and the caudal plane 639 form a 20° angle.

[0135] The intermediate components 610, 620, and 630 and the joint components 611, 621, and 631 can be assembled as required for the respective patient.

[0136] Different inclinations and offsets of the intermediate component 610, 620, 630, and joint component 611, 621, 631 allow the surgeon to adapt the configuration to a specific case.

[0137] In the embodiments illustrated in FIGS. 6 to 11 both the intermediate components and the joint components are provided in different inclinations. As previously explained, it is therefore possible to adjust the orientation of the articular joint by choosing the inclined intermediate components 610, 620, 630, and joint components 611, 621, 631. Further, the inclination to the anchoring member or angle between the longitudinal axis of the anchoring member central axis of the joint surface may be adjusted at the level of the intermediate component and/or the level of the joint component. For example, the plane defined by the rim 515 of the intermediate component 512 may be inclined in relation to the interface surface 7 of the anchoring member 1 (FIG. 9) and/or the plane defined by the rim 525 of the joint component 519 may be inclined in relation to the rim 515 of the intermediate component 512.

[0138] It is to be noted that the embodiments shown in FIGS. 7A, 7B, 9A, and 9B show exemplary embodiments using snap-fit connections as fixation member 414 and 514, while the embodiments shown in FIG. 11 have taper connections 614, 624, 634. The former may preferably be used as trial components whereas the latter may preferably be used as functional components, i. e. components that remain implanted.

LIST OF REFERENCE SIGNS

[0139] 1 Anchoring member [0140] 3 Proximal interface part [0141] 5 Distal portion [0142] 7 Interface surface [0143] 12 Fixation member [0144] 14 Fixation member [0145] 15 Stem portion [0146] 16 Fin [0147] 18 Central hole [0148] 19 Joint component [0149] 20 Indexing structure [0150] 22 Proximal engagement portion [0151] 22 Proximal engagement portion [0152] 50 Anchoring member [0153] 100 Joint member [0154] 101 Joint member with offset fixation member [0155] 102 Proximal End [0156] 104 Distal interface part [0157] 106 Indexing protrusion [0158] 108 Convex interface surface [0159] 111 Suture holes [0160] 112 Intermediate part [0161] 115 Fixation member [0162] 150 Joint member [0163] 301 Proximal part [0164] 302 Distal part [0165] 305 Protrusion [0166] 400 Joint replacement component [0167] 430, 530 Joint member [0168] 412, 512 Intermediate component [0169] 419, 519 Joint component [0170] 414, 514 Fixation member [0171] 420, 520 Mounting recess [0172] 421, 521 Protrusion [0173] 515 Rim of intermediate component [0174] 525 Rim of joint component [0175] 506 Indexing protrusion [0176] 604 Fixation member [0177] 610, 620, 630 Intermediate component [0178] 611, 621, 631 Joint component [0179] 614, 624, 634 Fixation member [0180] 616, 626 Plane [0181] 618, 628, 638 Cranial plane [0182] 619, 629, 639 Caudal plane