1、BS ISO 7206-12:2016 Implants for surgery Partial and total hip joint prostheses Part 12: Deformation test method for acetabular shells BSI Standards Publication WB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06BS ISO 7206-12:2016 BRITISH STANDARD National foreword This British Standard is the
2、 UK implementation of ISO 7206-12:2016. The UK participation in its preparation was entrusted to T 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 t Replacements. A list of organizations represented on this committee can be obtained on requ
3、est to its secretary. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. The British Standards Institution 2016. Published by BSI Standards Limited 2016 ISBN 978 0 580 85595 5 ICS 11.040.40 Compliance with a Bri
4、tish Standard cannot confer immunity from legal obligations. This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 September 2016. Amendments/corrigenda issued since publication Date T e x t a f f e c t e dBS ISO 7206-12:2016 ISO 2016 Implants f
5、or surgery Partial and total hip joint prostheses Part 12: Deformation test method for acetabular shells Implants chirurgicaux Prothses partielles et totales de larticulation de la hanche Partie 12: Mthode dessai de dformation des cupules actabulaires INTERNATIONAL STANDARD ISO 7206-12 First edition
6、 2016-10-01 Reference number ISO 7206-12:2016(E)BS ISO 7206-12:2016ISO 7206-12:2016(E)ii ISO 2016 All rights reserved COPYRIGHT PROTECTED DOCUMENT ISO 2016, Published in Switzerland All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise i
7、n 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 ISOs member body in the country of the requester. ISO copyright office Ch. de
8、 Blandonnet 8 CP 401 CH-1214 Vernier, Geneva, Switzerland Tel. +41 22 749 01 11 Fax +41 22 749 09 47 copyrightiso.org www.iso.orgBS ISO 7206-12:2016ISO 7206-12:2016(E)Foreword iv Introduction v 1 Scope . 1 2 Normative references 1 3 T erms and definitions . 1 4 Principle 3 5 Apparatus . 3 6 Procedur
9、e. 5 7 Report 6 Bibliography 8 ISO 2016 All rights reserved iii Contents PageBS ISO 7206-12:2016ISO 7206-12:2016(E) Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standa
10、rds 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 tak
11、e 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 pa
12、rticular the different approval criteria needed for the 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 o
13、f this document may be the subject of patent rights. ISO 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
14、 www.iso.org/patents). Any trade name used in this document 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 conformit y assessment, as well as information about ISOs adherence
15、 to the World Trade Organization (WTO) principles in the Technical 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 f
16、ollowing 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 and performance of st
17、emmed 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 components Part 13: Determination of re
18、sistance to torque of head fixation of stemmed femoral componentsiv ISO 2016 All rights reservedBS ISO 7206-12:2016ISO 7206-12:2016(E) Introduction Press-fit fixation is currently a common method for implanting non-cemented acetabular component for total hip joint replacement. In such a press-fit sy
19、stem, primary fixation of the acetabular component is achieved 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 fixat
20、ion, but also causes deformation of both the bone of the acetabular 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 r
21、egions of ilium and ischium, 4the deformation of the acetabular component 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 com
22、ponent tends to get in oval shape when looking onto its front 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 ant
23、i-rotation elements on the acetabular components outside as fins and 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 acet
24、abular component in a modular acetabular component system can affect 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. 3 469Deformation o
25、f the acetabular component in a monoblock cup system definitely results 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 sys
26、tem. 2578Acetabular component deformation can even then affect the systems 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 a
27、s 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
28、 a threshold today. It has to be considered that the test conditions described 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
29、Part 12: Deformation test method for acetabular shells 1 Scope 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 t
30、hat the important parameters that affect the components are taken into account 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 m
31、ethod is intended to be used to evaluate the comparison of various designs and 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
32、 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 specimen. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensab
33、le for its application. For dated references, only the edition cited applies. For 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 indications
34、ISO 7206-1, Implants for surgery Partial and total hip joint prostheses Part 1: Classification and designation of dimensions ISO 7206-2, Implants for surgery Partial and total hip joint prostheses Part 2: Articulating surfaces made of metallic, ceramic and plastics materials ISO 21534, Non-active su
35、rgical implants Joint replacement implants Particular requirements 3 T erms a nd definiti ons For the purposes of this document, the terms and definitions given in ISO 7206-1, ISO 7206-2 and ISO 21534 and the following, apply. 3.1 metal backing deformation amount of geometrical deviation (inner diam
36、eter and circularity of metal backing in a defined measurement plane) from design specifications under loading conditions INTERNATIONAL ST ANDARD ISO 7206-12:2016(E) ISO 2016 All rights reserved 1BS ISO 7206-12:2016ISO 7206-12:2016(E) 3.2 spherical socket deformation articulating surface deformation
37、 amount of geometrical deviation (diameter and circularity in a defined measurement plane) from design specifications under loading conditions 3.3 frontal face reference plane plane, perpendicular to the component polar axis, nominally at the frontal face level (see Figure 1 a) Note 1 to entry: In c
38、ase of doubt, the polar axis can be defined as perpendicular to the plane spanning around the contact 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 asym
39、metrically shaped front face, e.g. anatomically shaped acetabular components, the frontal face reference 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 f
40、rontal face does not contain any part perpendicular to the component axis, the frontal face reference plane 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) area
41、s of the frontal face are located in the reference plane. Figure 1 Frontal face reference plane of acetabular components 3.4 loading plane plane, 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 a
42、nd fully seated intraoperatively EXAMPLE For symmetrically shaped acetabular components, Figure 1 a), the loading 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) 3.5 measurement plane plane, parallel to the
43、frontal face reference plane, located with a certain distance to the frontal face reference plane but as close as possible to the frontal face reference plane Note 1 to entry: The sensitivity of the deformation measurement decreases with increasing distance of the measurement plane from the front fa
44、ce reference plane and with decreasing distance of the measurement plane to the top of the cup. Note 2 to entry: Within 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 captu
45、ring the measurement points is not disturbed by any design features of the test specimen as holes or cut-outs. The measurement points can be captured at the test specimen directly; they cannot be captured at the load frame. 4 Principle The test specimen is subjected to diametrically opposite two-poi
46、nt loading. For the determination of short-term deformation, measurements of diameter in loading direction in a defined 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
47、 rotation angles of itself, of which each rotation angle measures 120 to account for influence of asymmetric design features 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 aff
48、ect the tribology. So such components shall be tested in two steps: first step, testing of the metal backing alone; second 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 arti
49、cular surface which may affect tribology. Such components shall be tested in only one step. 5 Apparatus 5.1 Loading device A 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 t
