1、BS ISO 7206-12:2016Implants for surgery Partial and total hip joint prostheses Part 12: Deformation test method foracetabular shellsBSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06BS ISO 7206-12:2016 BRITISH STANDARDNational forewordThis British Standard is the UK im
2、plementation of ISO 7206-12:2016.The UK participation in its preparation was entrusted toT e c h n i c a l C o m m i t t e e C H / 1 5 0 / 4 , S u r g i c a l I m p l a n t s - B o n e a n d J o i n tReplacements.A list of organizations represented on this committee can beobtained on request to its
3、secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2016.Published by BSI Standards Limited 2016ISBN 978 0 580 85595 5ICS 11.040.40Compliance with a British Standard cann
4、ot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 30 September 2016.Amendments/corrigenda issued since publicationDate T e x t a f f e c t e dBS ISO 7206-12:2016 ISO 2016Implants for surgery Partial and t
5、otal hip joint prostheses Part 12: Deformation test method for acetabular shellsImplants chirurgicaux Prothses partielles et totales de larticulation de la hanche Partie 12: Mthode dessai de dformation des cupules actabulairesINTERNATIONAL STANDARDISO7206-12First edition2016-10-01Reference numberISO
6、 7206-12:2016(E)BS ISO 7206-12:2016ISO 7206-12:2016(E)ii ISO 2016 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2016, Published in SwitzerlandAll rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electr
7、onic 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 ISOs member body in the country of the requester.ISO copyright officeCh. de Blandonnet 8 CP 401CH-1214 Vernier,
8、 Geneva, SwitzerlandTel. +41 22 749 01 11Fax +41 22 749 09 47copyrightiso.orgwww.iso.orgBS ISO 7206-12:2016ISO 7206-12:2016(E)Foreword ivIntroduction v1 Scope . 12 Normative references 13 Terms and definitions . 14 Principle 35 Apparatus . 36 Procedure. 57 Report 6Bibliography 8 ISO 2016 All rights
9、reserved iiiContents PageBS ISO 7206-12:2016ISO 7206-12:2016(E)ForewordISO (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 comm
10、ittees. 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
11、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
12、 different types of ISO documents 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).Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO
13、 shall not be held responsible for identifying any or all such patent rights. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents).Any trade name used in this docume
14、nt is information given for the convenience of users and does not constitute an endorsement.For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the World Trade Organization (WTO) principles in the Te
15、chnical Barriers to Trade (TBT) see the following URL: www.iso.org/iso/foreword.html.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
16、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 and performance of stemmed femoral components Part 6: Endurance properties testing
17、 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 components Part 13: Determination of resistance to torque of head fixation of stemmed femoral compon
18、entsiv ISO 2016 All rights reservedBS ISO 7206-12:2016ISO 7206-12:2016(E)IntroductionPress-fit fixation is currently a common method for implanting non-cemented acetabular component for total hip joint replacement. In such a press-fit system, primary fixation of the acetabular component is achieved
19、by an interference fit between the acetabular hip cup and the reamed acetabular base.1The interference, diameter difference, leads to a certain amount of pressure between bone and acetabular component that determines the amount of fixation, but also causes deformation of both the bone of the acetabu
20、lar base and the acetabular component. The amount of interference is specifically defined for the appropriate acetabular component.Due to the anisotropic mechanical properties of the acetabular bone, increased stiffness mainly in the regions of ilium and ischium,4the deformation of the acetabular co
21、mponent does not occur homogenously. The local deformation of the acetabular component is increased in areas where the acetabular component is in contact with bone regions of increased stiffness. Therefore, the deformed acetabular component tends to get in oval shape when looking onto its front face
22、.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 components outside as fins an
23、d grooves.3489Screw holes and any kind of asymmetrically positioned cut-outs could also affect the cups deformation behaviour leading to differences in the amount of deformation depending on load orientation.Deformation of the acetabular component in a modular acetabular component system can affect
24、the proper seating and locking of the articulating insert, as well as the lubrication and friction properties of the articulating surfaces, if there also occurs a deformation of the articulating spherical socket.3469Deformation of the acetabular component in a monoblock cup system definitely results
25、 in a deformation of the articulating spherical socket potentially affecting lubrication and friction properties of the articulating surfaces, potentially resulting in higher wear rates and premature failure of the prosthesis system.2578Acetabular component deformation can even then affect the syste
26、ms performance if the deformation itself is not recognizable for the surgeon.Therefore, it is important to ensure that the deformation of an acetabular component does not significantly affect the systems functional properties as intraoperative assembly of components, tribology, etc. This method addr
27、esses 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 has to be considered that the test conditions desc
28、ribed in this part of ISO 7206 do not exactly reproduce all the factors of the clinical situation. ISO 2016 All rights reserved vBS ISO 7206-12:2016BS ISO 7206-12:2016Implants for surgery Partial and total hip joint prostheses Part 12: Deformation test method for acetabular shells1 ScopeThis part of
29、 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 acco
30、unt and it describes how the specimen is set up for testing. Furthermore, this part of ISO 7206 specifies the test parameters of press-fit acetabular components tested in accordance with this part of ISO 7206.The described method is intended to be used to evaluate the comparison of various designs a
31、nd materials used for acetabular components in total hip joint replacement when tested under similar conditions.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
32、 performance.This part of ISO 7206 does not cover methods of examining the test specimen.2 Normative referencesThe following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. Fo
33、r undated references, the latest edition of the referenced document (including any amendments) applies.ISO 2768-2, General tolerances Part 2: Geometrical tolerances for features without individual tolerance indicationsISO 7206-1, Implants for surgery Partial and total hip joint prostheses Part 1: Cl
34、assification and designation of dimensionsISO 7206-2, Implants for surgery Partial and total hip joint prostheses Part 2: Articulating surfaces made of metallic, ceramic and plastics materialsISO 21534, Non-active surgical implants Joint replacement implants Particular requirements3 Terms and defini
35、tionsFor the purposes of this document, the terms and definitions given in ISO 7206-1, ISO 7206-2 and ISO 21534 and the following, apply.3.1metal backing deformationamount of geometrical deviation (inner diameter and circularity of metal backing in a defined measurement plane) from design specificat
36、ions under loading conditionsINTERNATIONAL STANDARD ISO 7206-12:2016(E) ISO 2016 All rights reserved 1BS ISO 7206-12:2016ISO 7206-12:2016(E)3.2spherical socket deformationarticulating surface deformationamount of geometrical deviation (diameter and circularity in a defined measurement plane) from de
37、sign specifications under loading conditions3.3frontal face reference planeplane, perpendicular to the component polar axis, nominally at the frontal face level (see Figure 1 a)Note 1 to entry: In case of doubt, the polar axis can be defined as perpendicular to the plane spanning around the contact
38、zone of the acetabular component to the cortical bone, and as containing the centre point of the ball sphere approximating the acetabular components outer sphere.Note 2 to entry: In case of an asymmetrically shaped front face, e.g. anatomically shaped acetabular components, the frontal face referenc
39、e plane can be located at a level, which contains the largest part of the frontal face that is perpendicular to the component polar axis (see Figure 1 b) and c).Note 3 to entry: In case that the frontal face does not contain any part perpendicular to the component axis, the frontal face reference pl
40、ane can be located at that level at the approximated middle between the highest and the lowest point of the frontal face in distal direction (see Figure 1 d).a) b)c) d)NOTE Marked (shaded) areas of the frontal face are located in the reference plane.Figure 1 Frontal face reference plane of acetabula
41、r components3.4loading planeplane, parallel to the frontal face reference plane and located in an area where the acetabular cup gets in contact with the cortical bone after being properly and fully seated intraoperativelyEXAMPLE For symmetrically shaped acetabular components, Figure 1 a), the loadin
42、g plane will usually be located close to the frontal face reference plane.2 ISO 2016 All rights reservedBS ISO 7206-12:2016ISO 7206-12:2016(E)3.5measurement planeplane, parallel to the frontal face reference plane, located with a certain distance to the frontal face reference plane but as close as p
43、ossible to the frontal face reference planeNote 1 to entry: The sensitivity of the deformation measurement decreases with increasing distance of the measurement plane from the front face reference plane and with decreasing distance of the measurement plane to the top of the cup.Note 2 to entry: With
44、in the measurement plane, the measurement points for determining the inner diameter of the test specimen can be captured. Therefore, the measurement plane can be defined so that capturing the measurement points is not disturbed by any design features of the test specimen as holes or cut-outs. The me
45、asurement points can be captured at the test specimen directly; they cannot be captured at the load frame.4 PrincipleThe test specimen is subjected to diametrically opposite two-point loading. For the determination of short-term deformation, measurements of diameter in loading direction in a defined
46、 measurement plane are carried out prior and under loading, as well as after unloading. This deformation measurement procedure is repeated two times after rotating the specimen with rotation angles of itself, of which each rotation angle measures 120 to account for influence of asymmetric design fea
47、tures as fins, holes, etc.Metal-backed modular acetabular components can deform and affect the seating of the insert. The combination of metal-backing and insert can deform and affect the tribology. So such components shall be tested in two steps: first step, testing of the metal backing alone; seco
48、nd step, testing of the metal backing with the appropriately mounted bearing insert.Press-fit installation of monoblock acetabular cup components can cause deformation of the articular surface which may affect tribology. Such components shall be tested in only one step.5 Apparatus5.1 Loading deviceA
49、 load frame capable of the following functionality:a) shall not exhibit any visible and irreversible deformation under loading the test specimen;b) shall allow reproducible loading and unloading of a test specimen along a defined mechanical axis and measuring loads and distances, respectively;c) shall be capable of loading acetabular hip cups up to a diameter of 100 mm and a height of 50 mm. ISO 2016 All rights reserved 3BS ISO 7206-12:2016ISO 7206-12:2016(E)Figure 2 Example of a
