ISO 7206-13:2016
(Main)Implants for surgery — Partial and total hip joint prostheses — Part 13: Determination of resistance to torque of head fixation of stemmed femoral components
Implants for surgery — Partial and total hip joint prostheses — Part 13: Determination of resistance to torque of head fixation of stemmed femoral components
ISO 7206-13:2016 describes a method of determining the torque required, under specified laboratory conditions, to loosen the fixation of the head of hip joint prostheses in which the head is not intended to rotate relative to the neck. It applies to the femoral component of total or partial hip joint replacements in which the head and neck/stem (in the following referred to as cone) are secured together by a locking conical taper or any other means and in which the head and cone are separate components, and which are made of metallic or non-metallic materials. It does not cover methods of examining the test specimens; these should be agreed between the test laboratory and the party submitting the specimen for test.
Implants chirurgicaux — Prothèses partielles et totales de l'articulation de la hanche — Partie 13: Détermination de la résistance au couple de la fixation des têtes des tiges fémorales
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Standards Content (Sample)
INTERNATIONAL ISO
STANDARD 7206-13
First edition
2016-07-01
Implants for surgery — Partial and
total hip joint prostheses —
Part 13:
Determination of resistance to torque
of head fixation of stemmed femoral
components
Implants chirurgicaux — Prothèses partielles et totales de
l’articulation de la hanche —
Partie 13: Détermination de la résistance au couple de la fixation des
têtes des tiges fémorales
Reference number
ISO 7206-13:2016(E)
©
ISO 2016
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ISO 7206-13:2016(E)
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ii © ISO 2016 – All rights reserved
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ISO 7206-13:2016(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Apparatus . 1
6 Procedure. 2
6.1 Test specimen and sample size . 2
6.2 Assembly of test specimen (installation) . 2
6.3 Head fixation . 2
6.4 Torque of head fixation . 3
6.5 Performance criteria . 3
6.6 Test report . 3
7 Disposal of test specimens . 4
Bibliography . 6
© ISO 2016 – All rights reserved iii
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ISO 7206-13:2016(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
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electrotechnical standardization.
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Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information
The committee responsible for this document is ISO/TC 150, Implants for surgery, Subcommittee SC 4,
Bone and joint replacements.
ISO 7206 consists of the following parts, under the general title Implants for surgery — Partial and total
hip joint prostheses:
— Part 1: Classification and designation of dimensions
— Part 2: Articulating surfaces made of metallic, ceramic and plastics materials
— Part 4: Determination of endurance properties of stemmed femoral components
— Part 6: Endurance properties testing and performance requirements of neck region of stemmed femoral
components
— Part 10: Determination of resistance to static load of modular femoral heads
— Part 12: Deformation test method for acetabular shells
— Part 13: Determination of resistance to torque of head fixation of stemmed femoral components
iv © ISO 2016 – All rights reserved
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ISO 7206-13:2016(E)
Introduction
Some designs of stemmed femoral components of total hip joint prostheses comprise a
stem/neck component and a bearing head component, which is commonly in the form of a partial
sphere incorporating a female fixation feature for attachment to the neck of the stem. Such heads are
generally produced using metal or ceramic material. It is important that after assembly, whether by
the manufacturer or by the surgeon in the operating theatre, the head subsequently remains immobile
on the neck, because movement of a metal or a ceramic femoral head component on a metal stem/neck
component will cause the metal components to wear, while metal-on-metal movement may lead to
severe fretting corrosion (see Reference [1]).
It is essential, therefore, that the strength of the fixation between the head and the neck is sufficient
to withstand the torque likely to be transmitted through the prosthesis in use. The maximum torque
applied to the interface connection depends on several design, material, and manufacturing specific
parameters, e.g. pairing of bearing materials, bearing diameter, and clearance, surface finish, etc. (see
Reference [2]).
The locking strength of the interface connection depends on several design, material, and manufacturing
specific parameters for the taper geometry of the mating components, as taper angle and tolerances, taper
clearance, surface finish, etc. In consequence, the torsional locking strength of nominal identical taper
fixations might vary significantly (see Reference [3]) and needs to be determined prior to clinical use.
Clinical failure of taper connections is related to particle generation by interface micromotion, fretting,
and fatigue failure (see Reference [4]). Torsional interface stability is essential for stable fixation of
taper connections in order to limit the above listed adverse effects.
© ISO 2016 – All rights reserved v
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INTERNATIONAL STANDARD ISO 7206-13:2016(E)
Implants for surgery — Partial and total hip joint
prostheses —
Part 13:
Determination of resistance to torque of head fixation of
stemmed femoral components
1 Scope
This part of ISO 7206 describes a method of determining the torque required, under specified laboratory
conditions, to loosen the fixation of the head of hip joint prostheses in which the head is not intended to
rotate relative to the neck. It applies to the femoral component of total or partial hip joint replacements
in which the head and neck/stem (in the following referred to as cone) are secured together by a locking
conical taper or any other means and in which the head and cone are separate components, and which
are made of metallic or non-metallic materials.
This part of ISO 7206 does not cover methods of examining the test specimens; these should be agreed
between the test laboratory and the party submitting the specimen for test.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only t
...
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