ISO/FDIS 7206-12
(Main)Implants for surgery — Partial and total hip joint prostheses — Part 12: Deformation test method for press-fit acetabular components
Implants for surgery — Partial and total hip joint prostheses — Part 12: Deformation test method for press-fit acetabular components
This part of ISO 7206 specifies a test method for determining short-term deformation of a press-fit acetabular component for total hip joint replacement under specific laboratory conditions. It also defines the conditions of testing so that the important parameters that affect the components are taken into account and it describes how the specimen is set up for testing. The described method is intended to be used to measure the amount of deformation under load and plastic deformation after unloading of various designs and materials used for acetabular components in total hip joint replacement. These measurements are then used in an evaluation of risks associated with acetabular cup deformation for the acetabular component under evaluation to determine if its performance can be adversely affected. In the evaluation of risks associated with acetabular component deformation, it can be useful to take into consideration various design, material, and surgical implantation factors (for example, those identified in Clause 8), and, if necessary, a comparison of results to a reference implant tested under the same conditions. Depending on this evaluation, additional testing and/or clinical data, which is outside the scope of this document, can be necessary. The loading of the acetabular components in vivo will, in general, differ from the loading defined in this test method. The results obtained here cannot be used to directly predict in vivo performance. This part of ISO 7206 does not cover methods of examining the test specimens.
Implants chirurgicaux — Prothèses partielles et totales de l'articulation de la hanche — Partie 12: Méthode d’essai de déformation des composants acétabulaires sans ciment
ISO 7206-12:2016 spécifie une méthode d'essai permettant de déterminer la déformation à court-terme d'un composant acétabulaire «pressfit» pour une prothèse totale de l'articulation de la hanche dans des conditions expérimentales spécifiques. Elle définit également les conditions d'essai de manière que les paramètres importants qui influent sur les composants soient pris en compte, et décrit en outre le montage d'essai de l'éprouvette. De plus, la présente partie de l'ISO 7206 spécifie les paramètres d'essai des composants acétabulaires «pressfit» soumis à l'essai conformément à la présente partie de l'ISO 7206. La méthode décrite est destinée à être utilisée pour évaluer la comparaison des différentes conceptions et des matériaux utilisés pour les composants acétabulaires d'une prothèse totale de l'articulation de la hanche en cas d'essai dans des conditions similaires. La mise en charge des composants acétabulaires in vivo diffèrera, en règle générale, de celle définie dans la présente méthode d'essai. Les résultats obtenus ici ne peuvent pas être utilisés directement pour prédire la performance in vivo. ISO 7206-12:2016 ne traite pas des méthodes d'examen de l'éprouvette.
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Standards Content (Sample)
FINAL DRAFT
International
Standard
ISO/TC 150/SC 4
Implants for surgery — Partial and
Secretariat: BSI
total hip joint prostheses —
Voting begins on:
2025-08-21
Part 12:
Deformation test method for press-
Voting terminates on:
2025-10-16
fit acetabular components
RECIPIENTS OF THIS DRAFT ARE INVITED TO SUBMIT,
WITH THEIR COMMENTS, NOTIFICATION OF ANY
RELEVANT PATENT RIGHTS OF WHICH THEY ARE AWARE
AND TO PROVIDE SUPPOR TING DOCUMENTATION.
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BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO-
LOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT
INTERNATIONAL STANDARDS MAY ON OCCASION HAVE
TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL
TO BECOME STAN DARDS TO WHICH REFERENCE MAY BE
MADE IN NATIONAL REGULATIONS.
Reference number
FINAL DRAFT
International
Standard
ISO/TC 150/SC 4
Implants for surgery — Partial and
Secretariat: BSI
total hip joint prostheses —
Voting begins on:
Part 12:
Deformation test method for press-
Voting terminates on:
fit acetabular components
RECIPIENTS OF THIS DRAFT ARE INVITED TO SUBMIT,
WITH THEIR COMMENTS, NOTIFICATION OF ANY
RELEVANT PATENT RIGHTS OF WHICH THEY ARE AWARE
AND TO PROVIDE SUPPOR TING DOCUMENTATION.
© ISO 2025
IN ADDITION TO THEIR EVALUATION AS
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO-
LOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
INTERNATIONAL STANDARDS MAY ON OCCASION HAVE
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL
or ISO’s member body in the country of the requester.
TO BECOME STAN DARDS TO WHICH REFERENCE MAY BE
MADE IN NATIONAL REGULATIONS.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland Reference number
ii
Contents Page
Foreword .iv
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Principle . 3
5 Apparatus . 3
5.1 Loading device .3
5.2 Test specimen selection .6
5.3 Number of samples and testing conditions .6
6 Procedure . 6
7 Test report . 7
8 Interpretation of results . 8
Bibliography . 9
iii
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee
has been established has the right to be represented on that committee. International organizations,
governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely
with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO document should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 150, Implants for surgery, Subcommittee SC 4,
Bone and joint replacements.
This second edition cancels and replaces the first edition (ISO 7206-12:2016), which has been technically
revised.
The main changes are as follows:
— the third element of the title has been aligned with the scope which states that this test is for press-fit
acetabular components;
— the terminology has been aligned with ISO 21535:2023;
— the scope has been revised to clarify that the deformation measurements that are made in this test
and how these measurements are then used in an evaluation of risks associated with acetabular cup
deformation to determine if acetabular component performance can be adversely affected;
— the term “metal backing deformation” has been changed to “metal shell deformation” and the term
“spherical socket deformation” has been deleted in Clause 3;
— a requirement for the clamping jaw material to have a minimum hardness of 60 HRC has been added in 5.1;
— the requirement to test all liner articulating surface materials has been changed to a recommendation
and a requirement has been added to justify why each liner material was not tested in 5.2;
— a new subclause, “5.3 Number of samples and testing conditions”, has been added and corresponding
information has been moved to this subclause;
— in Clause 6, the starting rotational orientation for symmetric and asymmetric specimens have been
clarified and tolerances have been added to the rotational orientations where needed, a minimum
loading rate has been added, a clarification has been added regarding the 0,2 % deformation stopping
criterion, the steps for testing monobloc and modular acetabular components have been clarified and
corresponding procedure steps have been added;
iv
— in Clause 7, reporting requirements including requirements to justify the worst-case acetabular
components used during testing and the worst-case directions of loading have been added, reporting
requirements for the year of publication, any unusual observations during testing, and the date of the
test have been added, and the requirement to report stiffness of the testing setup has been removed;
— a new Clause, “8 Interpretation of results”, has been added to include examples of factors to consider
in an evaluation of risks associated with acetabular component deformation under load and plastic
deformation after unloading, and, based on the measured deformation test results, a requirement has
been added to perform an evaluation to determine whether or not implant performance can be adversely
affected.
A list of all parts in the ISO 7206 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
v
Introduction
Press-fit fixation is currently a common method for implanting a non-cemented acetabular component
for total hip joint replacement. In such a press-fit acetabular component, primary fixation is achieved by
[1]
an interference fit between the acetabular cup and the reamed acetabulum. The interference, diameter
difference, leads to a certain amount of pressure between bone and acetabular component that contributes
to the amount of fixation, but also causes deformation of both the bone of the acetabulum and the acetabular
component. The amount of interference is based on the design of the reamer and acetabular cup, is known
by the manufacturer and can be included in the surgical technique manual.
The anisotropic mechanical properties of the acetabular bone, with increased stiffness mainly in the regions
[2]
of ilium and ischium, and variable geometry of the acetabulum, can create the potential for inhomogeneous
deformation of the acetabular component. The local deformation of the acetabular component can be
increased in areas where the acetabular component is in contact with bone regions of increased stiffness.
Therefore, the deformed acetabular component can be oval in shape when looking onto its frontal face.
There are design features beside the cup-bone-interference and the bone stiffness that affect the
deformation of the acetabular component. These design features include, among others, the cup diameter,
wall thickness, material and anti-rotation elements on the acetabular component’s outer surface such as
[2][3][4][5]
fins and grooves. Screw holes and any kind of asymmetrically positioned cut-outs could also affect
the cup’s deformation behaviour leading to differences in the amount of deformation depending on the cup’s
rotational orientation around its polar axis under loading.
Deformation of a modular acetabular component can affect the proper seating and locking of the articulating
[3]
liner. Additionally, articulating surface deformation can affect the lubrication and friction properties.
[4][5][6]
Deformation of a monobloc acetabular cup definitely results in articulating surface deformation
[7]
potentially affecting lubrication and friction properties, potentially resulting in higher wear rates and
[ ][ ][ ]
premature failure of the prosthesis. 3 8 9 Therefore, acetabular component deformation has the potential
to affect the hip replacement’s performance.
Therefore, it is important to ensure that the deformation of an acetabular component does not significantly
affect the hip replacement’s functional properties as intraoperative assembly of components, tribology, etc.
This method addresses the short-term deformation performed under laboratory conditions. It does not give
a quantitative deformation limit as an acceptance criterion because there is no reliable data in the scientific
literature to support such a threshold today. It must be considered that the test conditions described in this
document do not exactly reproduce all the factors of the clinical situation.
vi
FINAL DRAFT International Standard ISO/FDIS 7206-12:2025(en)
Implants for surgery — Partial and total hip joint
prostheses —
Part 12:
Deformation test method for press-fit acetabular components
1 Scope
This document specifies a test method for determining short-term deformation of a press-fit acetabular
component for total hip joint replacement under specific laboratory conditions. It also defines the conditions
of testing so that the important parameters that affect the components are taken into account and it
describes how the specimen is set up for testing.
The described method is intended to be used to measure the amount of deformation under load and plastic
deformation after unloading of various designs and materials used for
...
ISO/DISFDIS 7206-12:2024(en)
ISO/TC 150/SC 4
Secretariat: BSI
Date: 2025-08-06
Implants for surgery — Partial and total hip joint prostheses — —
Part 12:
Deformation test method for press-fit acetabular components
Second edition
Date: 2024-11-05
FDIS stage
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication
may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying,
or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO
at the address below or ISO'sISO’s member body in the country of the requester.
ISO Copyright Officecopyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: + 41 22 749 01 11
Email: E-mail: copyright@iso.org
Website: www.iso.org
Published in Switzerland.
iii
Contents Page
Foreword . v
Introduction . vii
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Principle . 4
5 Apparatus . 4
5.1 Loading device . 4
5.2 Test specimen selection . 7
5.3 Number of samples and testing conditions . 7
6 Procedure . 8
7 Test report . 9
8 Interpretation of results . 10
Bibliography . 11
iv
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types of
ISO document should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent rights
in respect thereof. As of the date of publication of this document, ISO [had/had not] received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that this
may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 150, Implants for surgery, Subcommittee SC 4,
Bone and joint replacements.
This second edition cancels and replaces the first edition (ISO 7206-12:2016), which has been technically
revised.
The main changes are as follows:
— — Modified the third partelement of the title to alignhas been aligned with the scope which states that
this test is for press-fit acetabular components, as follows: “Part 12: Deformation test method for press-fit
acetabular components”.;
— — Harmonized the terminology has been aligned with ISO 21535:2023 throughout ;
the document.
— In the Introduction and Bibliography, re-ordered and modified references.
— — In Clause 1, the document now clarifiesscope has been revised to clarify that the deformation
measurements that are made in this test and how these measurements are then used in an evaluation of
risks associated with acetabular cup deformation to determine if acetabular component performance can
be adversely affected.;
— — In Clause 3, changed the term “metal backing deformation” has been changed to “metal shell
deformation” and deletedthe term “spherical socket deformation” has been deleted in 3”.;
— — In sub-clause 5.1, a requirement for the clamping jaw material to have a minimum hardness of 60 HRC
washas been added in 5.1.;
v
— — In sub-clause 5.2, the requirement to test all liner articulating surface materials washas been changed
to a recommendation and, if applicable, a requirement washas been added to justify why each liner
material was not tested in 5.2.;
— — Aa new sub-clause, “5.3subclause, “5.3 Number of samples and testing conditions”, washas been added
and corresponding information washas been moved to this sub-clause. For example, sample size
information and the requirement to test at room temperature under dry conditions was moved from
Clause 6 to sub-clause 5.3.subclause;
in 6— In Clause 6, clarified , the starting rotational orientation for symmetric and asymmetric
specimens have been clarified and tolerances werehave been added to the rotational orientations,
where needed. A, a minimum loading rate was identified. Clarification washas been added, a
clarification has been added regarding the 0,2 % deformation stopping criterion. Steps, the steps for
testing monobloc and modular acetabular components werehave been clarified and corresponding
procedure steps added.
— — In Clause 7,have been added;
— in 7, reporting requirements including requirements to justify the worst-case acetabular components used
during testing and the worst-case directions of loading. Also have been added, reporting requirements
were added for the year of publication, any unusual observations during testing, and the date of the test.
Also, removed have been added, and the requirement to report stiffness of the testing setup. has been
removed;
— — Aa new Clause, “8 “8 Interpretation of results”, washas been added to include examples of factors to
consider in an evaluation of risks associated with acetabular component deformation under load and
plastic deformation after unloading. Then, and, based on the measured deformation test results, a
requirement washas been added to perform an evaluation to determine whether or not implant
performance can be adversely affected.
A list of all parts in the ISO 7206 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
vi
Introduction
Press-fit fixation is currently a common method for implanting a non-cemented acetabular component for
total hip joint replacement. In such a press-fit acetabular component, primary fixation is achieved by an
[1]
[ ]
interference fit between the acetabular cup and the reamed acetabulum. 0. The interference, diameter
difference, leads to a certain amount of pressure between bone and acetabular component that contributes to
the amount of fixation, but also causes deformation of both the bone of the acetabulum and the acetabular
component. The amount of interference is based on the design of the reamer and acetabular cup, is known by
the manufacturer and can be included in the surgical technique manual.
The anisotropic mechanical properties of the acetabular bone, with increased stiffness mainly in the regions
[2]
[ ]
of ilium and ischium, 0, and variable geometry of the acetabulum, can create the potential for
inhomogeneous deformation of the acetabular component. The local deformation of the acetabular
component can be increased in areas where the acetabular component is in contact with bone regions of
increased stiffness. Therefore, the deformed acetabular component can be oval in shape when looking onto its
frontal face.
There are design features beside the cup-bone-interference and the bone stiffness that affect the deformation
of the acetabular component. These design features include, among others, the cup diameter, wall thickness,
material and anti-rotation elements on the acetabular component’s outer surface such as fins and grooves.
[2][3][4][5]
[ ][ ][ ][ ]
0 0 0 0. Screw holes and any kind of asymmetrically positioned cut-outs could also affect the cup’s
deformation behaviour leading to differences in the amount of deformation depending on the cup’s rotational
orientation around its polar axis under loading.
Deformation of a modular acetabular component can affect the proper seating and locking of the articulating
liner. Additionally, articulating surface deformation can affect the lubrication and friction
[3][4][5][6]
[ ][ ][ ][ ]
properties. 0 0 0 0. Deformation of a monobloc acetabular cup definitely results in articulating
[7]
[ ]
surface deformation potentially affecting lubrication and friction properties, 0, potentially resulting in
[3][8][9]
[ ][ ][ ]
higher wear rates and premature failure of the prosthesis. 0 0 0. Therefore, acetabular component
deformation has the potential to affect the hip replacement’s performance.
Therefore, it is important to ensure that the deformation of an acetabular component does not significantly
affect the hip replacement’s functional properties as intraoperative assembly of components, tribology, etc.
This method addresses the short-term deformation performed under laboratory conditions. It does not give a
quantitative deformation limit as an acceptance criterion because there is no reliable data in the scientific
literature to support such a threshold today. It must be considered that the test conditions described in this
document do not exactly reproduce all the factors of the clinical situation.
vii
Implants for surgery — Partial and total hip joint prostheses — Part
12: Deformation test method for press-fit acetabular components —
Part 12:
Deformation test method for press-fit acetabular components
1 Scope
This document specifies a test method for determining short-term deformation of a press-fit acetabular
component for total hip joint replacement under specific laboratory conditions. It also defines the conditions
of testing so that the important parameters that affect the components are taken into account and it describes
how the specimen is set up for testing.
The described method is intended to be used to measure the amount of deformation under load and plastic
deformation after unloading of various designs and materials used for acetabular components in total hip joint
replacement. These measurements are then used in an evaluation of risks associated with acetabular cup
deformation for the acetabular component under evaluation to determine if its performance can be adversely
affected. In the evaluation of risks associated with acetabular component deformation, it can be useful to take
into consideration various design, material, and surgical implantation factors (for example,e.g. those identified
in 8Clause 8),), and, if necessary, a comparison of results to a reference implant tested under the same
conditions. Depending on this evaluation, either additional testing and/or clinical data, or both, which is
outside the scope of this document, can be necessary.
The loading of the acetabular components in vivo will, in general, differ from the loading defined in this test
method. The results obtained here cannot be used to directly predict in vivo performance.
This document does not cover methods of examiningthat examine the test specimens.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements of this document. For dated references, only the edition cited applies. For undated references,
the latest edition of the r
...
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