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 anti torsion 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 anti

torsion 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 11 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 110 with locking screws 125.

[0032] A plurality of anti-torsion recesses 111 may be recessed in an inside edge of

the rim 108.

[0033]The prosthesis 100 comprises modularly interchangeable componentry

comprising the locking ring 110, a dual mobility liner 112 shown in Figure 4 and the

constrained liner 113 shown in Figure 5.

[0034] The dual mobility liner 112 generally has a thicker rim than that of the

constrained liner 113. Furthermore, a femoral head articular socket 114 of the dual

mobility liner 112 is generally more concentric than the more eccentric socket 114 of

the constrained liner 113.

[0035] Furthermore, the femoral head articular socket 114 of the dual mobility liner

112 is generally smaller than that of the constrained liner 113 to articularly engage a

smaller femoral head component 103.

[0036] The dual mobility liner 112 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 118 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 112 articularly engages the cup 107 in a non

constrained manner. In other words, the femoral head component 103 articulates

within the dual mobility liner 112 and the dual mobility liner 112 further articulates

within the cup 107.

[0040]According to the constrained configuration 116 shown in Figure 7, the

constrained liner 117 fits within the cup 107 to articularly engage the femoral head

component 103. Furthermore, the constrained liner 113 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

113 is locked within the cup 107 so that the constrained liner 113 does not articulate

within the cup 107.

[0041] The prosthesis 100 may be further configurable in the constrained dual mobility

configuration 119 shown in Figure 9. In accordance with this configuration 119, the

dual mobility liner 112 fits within the cup 107 to articularly engage the femoral head

component 103. However, the dual mobility liner 112 is restrained by the locking ring

110 engaging the rim 108.

[0042] The dual mobility liner 112 may be restrained by the locking ring 110 to prevent

the dual mobility liner 112 from dislocating from the cup 107. Alternatively, or

additionally, dual mobility liner 112 may be restrained by the locking ring to either

limit the range of motion of the dual mobility liner 112 or alternatively to lock the dual

mobility liner 112 in place so that the dual mobility liner 112 does not articulate within

the cup 107. In embodiments, a peripheral edge of the dual mobility liner 112 may

have a recess or formation (not shown) which may be engaged by the same or

adapted locking ring 112 to lock the dual mobility liner 112 in place.

[0043] With reference to Figure 12, the constrained liner 113 may comprise a plurality

of anti-torsion tabs 120 which fit into the anti-torsion recesses 111 of the cup 107.

[0044] In a preferred embodiment shown, the prosthesis 100 comprises a quadrant of

recesses 111 and tabs 120.

[0045]As is evident from Figure 11, each tab 120 is clamped in a corresponding

recess 111 by the locking ring 110 to prevent movement of the constrained liner 113.

[0046]As is further shown in Figures 12 and 14, the constrained liner 113 may

comprise expansive slits 121 so that the constrained liner 113 can expand when

accepting the femoral head component 103 therein. Thereafter, the slits 121 are held

closed by the locking ring 110.

[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 111 and be engaged by a pair of screws

125 either side of the recess 111.

[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 111 and be

engaged by at least one (but preferably two) screws 125 at one side of the anti-torsion

recess 111.

[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 115 for greater range of motion or the constrained

configuration 116 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 112.

[0056] For the constrained configurations 116, 119, 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 115 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

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.
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.
11. 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 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.