AU2022341082B2

AU2022341082B2 - Configurable revision acetabular prosthesis

Info

Publication number: AU2022341082B2
Application number: AU2022341082A
Authority: AU
Inventors: Declan Brazil; Christopher Burgess; Jeffrey Stambough; Benjamin Stronach
Original assignee: Signature Orthopaedics Europe Ltd
Current assignee: Signature Orthopaedics Europe Ltd
Priority date: 2021-12-17
Filing date: 2022-12-15
Publication date: 2024-01-04
Anticipated expiration: 2042-12-15
Also published as: WO2023108225A1; AU2022341082A1

Abstract

Configurable revision acetabular prosthesis has a flanged revision acetabular component defining a cup and a rim and modularly interchangeable componentry having a dual mobility liner, a constrained liner and a locking ring attachable to the rim. The cup and modularly interchangeable componentry are configured so that the prosthesis is configurable in a dual mobility configuration wherein the dual mobility liner fits within the cup to articularly engage a femoral head component and articularly engage the cup in a non-constrained manner or a constrained configuration wherein the constrained liner fits within the cup to articularly engage a femoral head component and be constrained by the locking ring engaging the rim so that the constrained liner engages the cup in a constrained manner. 11

Description

Configurable revision acetabular prosthesis

Field of the Invention

[0001 ] This invention relates generally to acetabular prosthesis and more particularly, this invention relates to configurable revision acetabular prosthesis.

Summary of the Disclosure

[0002] There is provided herein configurable acetabular prosthesis comprising a flanged revision acetabular component defining an articular cup which may be installed during revision surgery. The acetabular component comprises a plurality of flanges which secure the component around the acetabulum using bone screws.

[0003] The present prosthesis comprises modularly interchangeable componentry comprising a locking ring, dual mobility liner and constrained liner.

[0004] These modularly interchangeable components allow for configuration of the prosthesis in a dual mobility configuration wherein the dual mobility liner fits within the cup to articularly engage a femoral head component and to articularly engage the cup in a non-constrained manner.

[0005] The prosthesis is further configurable in a constrained configuration wherein the constrained liner fits within the cup to articularly engage a femoral head component and be constrained by the locking ring engaging the rim so that the constrained liner engages the cup in a constrained manner.

[0006] The cup and the modularly interchangeable componentry are configured for this interchangeability of configuration, including that both the dual mobility liner and the constrained liner have semispherical outer profiles matching a semispherical inner profile of the cup.

[0007] The prosthesis may yet further be configurable in a constrained dual mobility configuration wherein the dual mobility liner fits within the cup to articularly engage the femoral head component and be completely or somewhat restrained by the locking ring engaging the rim.

[0008] The constrained liner may comprise anti-torsion tabs which fit within antitorsion recesses recessed on inner sides of the rim. The anti-torsion tabs are clamped within respective recesses by the locking ring. The constrained liner and the dual mobility liner have the same outer diameter and the anti-torsion tabs extend beyond the outer diameter so that both the dual mobility and constrained liners can fit within the cup and, when the constrained liner fits within the cup, the tabs extend outwardly to fit within the recesses.

[0009] The prosthesis may further comprise a plurality of locking ring segments which may be installed at chosen circumferential positions of the rim to avoid impingement against a stem component. Each locking ring segment may comprise at least three screw holes so that each locking ring segment can be either installed across an antitorsion recess or alternatively with an end extending over an anti-torsion recess.

[0010] Other aspects of the invention are also disclosed.

Brief Description of the Drawings

[0011 ] Notwithstanding any other forms which may fall within the scope of the present invention, preferred embodiments of the disclosure will now be described, by way of example only, with reference to the accompanying drawings in which:

[0012] Figure 1 shows configurable revision acetabulum prosthesis;

[0013] Figure 2 shows a flanges revision acetabular component of the prosthesis;

[0014] Figure 3 shows a cross-sectional view of the acetabular component;

[0015] Figure 4 shows a dual mobility liner and femoral head component;

[0016] Figure 5 shows a constrained liner and femoral head component;

[0017] Figure 6 shows a cross-section of a dual mobility configuration of the prosthesis;

[0018] Figure 7 shows a cross-section of a constrained configuration of the prosthesis;

[0019] Figure 8 shows the dual ability configuration;

[0020] Figure 9 shows a constrained dual mobility configuration;

[0021 ] Figure 10 shows the constrained configuration;

[0022] Figure 1 1 shows a disassembled constrained configuration;

[0023] Figure 12 shows the constrained liner; [0024] Figures 13 and 14 show a constrained configuration using locking ring segments.

Description of Embodiments

[0025] Figure 1 shows configurable acetabular prosthesis 100 comprising a flanged revision acetabular component 101 . The component 101 engages different types of (typically polymeric) liners 102 which further engage a femoral head component 103 (typically ceramic) of a femoral stem component 104.

[0026] With reference to Figure 2, the component 101 comprises a plurality of flanges 105 and, according to the embodiment shown, comprises a minor flange 105C having one screw hole, an intermediate flange 105B having two screw holes and a domed major flange 105A having two rows of screw holes. The screw holes may be configured for engaging locking and non-locking bone screws.

[0027] The major flanges 105A preferably comprises as many screw holes as can reasonably fit within the space allowed, including for a ‘home run’ screw at an apex of the dome.

[0028] The component 101 comprises an osseo-integration backing 106 which may also extend behind the flanges 105.

[0029] The component 101 may be titanium and TiNi coated or an amorphous carbon material such as diamond-like carbon (DLC).

[0030] The component 101 defines a cup 107 defining a semispherical articular surface. The articular surface may be coated.

[0031 ] The cup 106 defines a rim 108 which may be flat and coplanar. The rim 108 comprises a plurality of circumferential locking ring holes 109 for engaging a locking ring 1 10 with locking screws 125.

[0032] A plurality of anti-torsion recesses 1 1 1 may be recessed in an inside edge of the rim 108.

[0033] The prosthesis 100 comprises modularly interchangeable componentry comprising the locking ring 1 10, a dual mobility liner 1 12 shown in Figure 4 and the constrained liner 1 13 shown in Figure 5. [0034] The dual mobility liner 1 12 generally has a thicker rim than that of the constrained liner 113. Furthermore, a femoral head articular socket 1 14 of the dual mobility liner 112 is generally more concentric than the more eccentric socket 114 of the constrained liner 1 13.

[0035] Furthermore, the femoral head articular socket 114 of the dual mobility liner 112 is generally smaller than that of the constrained liner 1 13 to articularly engage a smaller femoral head component 103.

[0036] The dual mobility liner 1 12 and the constrained liner 113 may be configured for articularly engaging a same type or a different type of femoral head component 103.

[0037] The modular interchangeable componentry and the cup 107 are configured so that the prosthesis 100 is interchangeably configurable in the dual mobility configuration 115 shown in Figures 6 and 8 and a constrained configuration 116 shown in Figures 7 and 10.

[0038] As is evident from Figures 6 and 7, both the dual mobility liner 112 and the constrained liner 113 have semispherical outer profiles 117 matching a semispherical inner profile 1 18 of the cup 107. In other words, each of the dual mobility liner 112 and constrained liner 113 further have the same outer diameter.

[0039] In the dual mobility configuration 115 shown in Figure 6, the dual mobility liner 117 fits within the cup 107 to articularly engage the femoral head component 103. Furthermore, the dual mobility liner 1 12 articularly engages the cup 107 in a nonconstrained manner. In other words, the femoral head component 103 articulates within the dual mobility liner 1 12 and the dual mobility liner 112 further articulates within the cup 107.

[0040] According to the constrained configuration 1 16 shown in Figure 7, the constrained liner 1 17 fits within the cup 107 to articularly engage the femoral head component 103. Furthermore, the constrained liner 1 13 is constrained by the locking ring 110 so that the constrained liner 113 engages the cup 107 in a constrained manner. In other words, in the constrained configuration 116, the femoral head component 103 articulates within the constrained liner 113 but the constrained liner 1 13 is locked within the cup 107 so that the constrained liner 1 13 does not articulate within the cup 107.

[0041 ] The prosthesis 100 may be further configurable in the constrained dual mobility configuration 1 19 shown in Figure 9. In accordance with this configuration 1 19, the dual mobility liner 1 12 fits within the cup 107 to articularly engage the femoral head component 103. However, the dual mobility liner 1 12 is restrained by the locking ring 1 10 engaging the rim 108.

[0042] The dual mobility liner 1 12 may be restrained by the locking ring 1 10 to prevent the dual mobility liner 1 12 from dislocating from the cup 107. Alternatively, or additionally, dual mobility liner 1 12 may be restrained by the locking ring to either limit the range of motion of the dual mobility liner 1 12 or alternatively to lock the dual mobility liner 1 12 in place so that the dual mobility liner 1 12 does not articulate within the cup 107. In embodiments, a peripheral edge of the dual mobility liner 1 12 may have a recess or formation (not shown) which may be engaged by the same or adapted locking ring 1 12 to lock the dual mobility liner 1 12 in place.

[0043] With reference to Figure 12, the constrained liner 1 13 may comprise a plurality of anti-torsion tabs 120 which fit into the anti-torsion recesses 1 1 1 of the cup 107.

[0044] In a preferred embodiment shown, the prosthesis 100 comprises a quadrant of recesses 1 1 1 and tabs 120.

[0045] As is evident from Figure 1 1 , each tab 120 is clamped in a corresponding recess 1 1 1 by the locking ring 1 10 to prevent movement of the constrained liner 1 13. [0046] As is further shown in Figures 12 and 14, the constrained liner 1 13 may comprise expansive slits 121 so that the constrained liner 1 13 can expand when accepting the femoral head component 103 therein. Thereafter, the slits 121 are held closed by the locking ring 1 10.

[0047] With reference to Figure 13, the prosthesis 100 may further comprise locking ring segments 122 attachable to the rim 108. In the embodiment shown, prosthesis 100 comprises three locking ring segments 122. [0048] The locking ring segments 122 may be installed at chosen circumferential positions to avoid the neck 123 of the stem component 104 to thereby reduce or prevent impingement.

[0049] Each locking ring component 122 preferably comprises three screw holes 124. [0050] As such, as is shown in Figure 14, a locking ring segment 122A may be installed to fit across an anti-torsion recess 1 1 1 and be engaged by a pair of screws 125 either side of the recess 1 1 1.

[0051 ] Alternatively, a locking ring segment 122B may be installed with an end of the locking ring segment 122B extending across an anti-torsion recess 1 1 1 and be engaged by at least one (but preferably two) screws 125 at one side of the anti-torsion recess 1 1 1.

[0052] The prosthesis 100 may be installed during revision surgery wherein a previously installed acetabular shell is replaced with the flanged revision acetabular component 101. The component 101 is secured around the acetabulum by bone screws 126 through the flanges 105.

[0053] Prior the revision surgery, the surgeon may have chosen the appropriate configuration of modularly interchangeable componentry for installation.

[0054] For example, using the prosthesis 100, the surgeon may choose to install the dual mobility configuration 1 15 for greater range of motion or the constrained configuration 1 16 for constrained mobility and reduced likelihood of dislocation.

[0055] Yet further, the surgeon may choose to install the constrained dual mobility configuration to reduce likelihood of dislocation and/or limit and/or restrain motion of the dual mobility liner 1 12.

[0056] For the constrained configurations 1 16, 1 19, the surgeon may alternatively choose to use the locking ring segments 122 and select installation positions thereof to avoid impingement.

[0057] Alternatively, the surgeon may choose the appropriate configuration during surgery by taking various anatomical and range of motion measurements during surgery. The various interchangeable componentry may be quickly selected and installed, including for trial installation. [0058] During trial installation, the prosthesis 100 may be reconfigured, such as by interchanging the dual mobility liner with constrained liner and the like.

[0059] Yet further, the prosthesis 100 may be reconfigured during further revision surgery wherein, for example, repeated dislocations may necessitate revision surgery to remove the dual mobility configuration 1 15 and install the constrained configuration 116.

[0060] The foregoing description, for purposes of explanation, used specific nomenclature to provide a thorough understanding of the invention. However, it will be apparent to one skilled in the art that specific details are not required in order to practise the invention. Thus, the foregoing descriptions of specific embodiments of the invention are presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed as obviously many modifications and variations are possible in view of the above teachings. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, thereby enabling others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is intended that the following claims and their equivalents define the scope of the invention.

Claims

1 . Configurable revision acetabular prosthesis comprising: a flanged revision acetabular component defining a cup and a rim, and modularly interchangeable componentry comprising: a dual mobility liner; a constrained liner; and a locking ring attachable to the rim, wherein the cup and modularly interchangeable componentry are configured, including that both the dual mobility liner and the constrained liner have semispherical outer profiles matching a semispherical inner profile of the cup, so that the prosthesis is configurable in: a dual mobility configuration wherein the dual mobility liner fits within the cup to: articularly engage a femoral head component; and articularly engage the cup in a non-constrained manner; or a constrained configuration wherein the constrained liner fits within the cup to: articularly engage a femoral head component; and be constrained by the locking ring engaging the rim so that the constrained liner engages the cup in a constrained manner.

2. The prosthesis as claimed in claim 1 , wherein the modularly interchangeable componentry is further configured so that the prosthesis is configurable in: a constrained dual mobility configuration wherein: the dual mobility liner fits within the cup to: articularly engage a femoral head component; and be restrained by the locking ring engaging the rim.

3. The prosthesis as claimed in claim 1 , wherein the cup defines a plurality of anti-torsion recesses recessed in from the rim and wherein the constrained liner comprises a plurality of anti-torsion tabs which fit into the anti-torsion recesses when the constrained liner fits within the cup.

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4. The prosthesis as claimed in claim 3, wherein the constrained liner and the dual mobility liner have the same outer diameter and the anti-torsion tabs extend beyond the outer diameter so that both the dual mobility and constrained liners may fit within the cup and, when the constrained liner fits within the cup, the tabs fit within the recesses.

5. The prosthesis as claimed in claim 3, wherein the cup defines a quadrant of anti-torsion recesses and the constrained liner comprises a corresponding quadrant of anti-torsion tabs.

6. The prosthesis as claimed in claim 3, wherein the rim comprises at least two locking ring screw holes between adjacent anti-torsion recesses.

7. The prosthesis as claimed in claim 1 , wherein a rim of the constrained liner comprises expansive slits.

8. The prosthesis as claimed in claim 1 , further comprising locking ring segments attachable to the rim.

9. The prosthesis as claimed in claim 8, wherein the cup defines a plurality of anti-torsion recesses and wherein each locking ring segment is configured to fit across an anti-torsion recess to constrain an anti-torsion tab of the constrained liner.

10. The prosthesis as claimed in claim 8, wherein the prosthesis comprises three locking ring segments.

1 1 . The prosthesis as claimed in claim 8, wherein each locking ring segment comprises three screw apertures.

12. The prosthesis as claimed in claim 8, wherein the cup defines a plurality of anti-torsion recesses and each locking ring segment comprises three screw apertures so that each locking ring segment can either: fit across an anti-torsion recess and be engaged by a pair of screws either side of the recess to constrain an anti-torsion tab of the constrained liner; have an end of the locking ring extend across and anti-torsion recess and be engaged by at least one screw at one side of the anti-torsion recess.

13. A method of configuring the prosthesis of claim 1 , the method comprising selecting either of the dual mobility liner in the constrained liner for installation in the

9 cup for configuring the prosthesis and the dual mobility configuration or constrained configuration respectively.

14. The method as claimed in claim 13, further comprising reconfiguring the prosthesis from the constrained configuration to the dual mobility configuration by replacing the constrained liner with the dual mobility liner.

15. The method as claimed in claim 13, further comprising reconfiguring the prosthesis from the dual mobility configuration to the constrained configuration by replacing the dual mobility liner with the constrained liner.

16. The method as claimed in claim 13, further comprising the prosthesis as claimed in claim 2 wherein the method further comprises selecting the dual mobility liner and the locking ring for the constrained dual mobility configuration.

17. The method as claimed in claim 13, further comprising the prosthesis as claimed in claim 8 further comprising choosing installation positions of the locking ring segments to avoid impingement.

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