1、BS ISO 14242-2:2016Implants for surgery Wear oftotal hip-joint prosthesesPart 2: Methods of measurementBSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06BS ISO 14242-2:2016 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 14242-2:2
2、016. It supersedes BS ISO 14242-2:2000 which is withdrawn.The UK participation in its preparation was entrusted to Tech-nical Committee CH/150/4, Surgical Implants - Bone and Joint Replacements.A list of organizations represented on this committee can be obtained on request to its secretary.This pub
3、lication 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 2016ISBN 978 0 580 93361 5 ICS 11.040.40 Compliance with a British Standard cannot confer immu
4、nity 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 publicationDate T e x t a f f e c t e dBS ISO 14242-2:2016 ISO 2016Implants for surgery Wear of total hip-joint p
5、rostheses Part 2: Methods of measurementImplants chirurgicaux Usure des prothses totales de larticulation de la hanche Partie 2: Mthodes de mesureINTERNATIONAL STANDARDISO14242-2Second edition2016-09-15Reference numberISO 14242-2:2016(E)BS ISO 14242-2:2016ISO 14242-2:2016(E)ii ISO 2016 All rights re
6、servedCOPYRIGHT 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, electronic or mechanical, including photocopying, or posting on the internet or an in
7、tranet, 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, Geneva, SwitzerlandTel. +41 22 749 01 11Fax +41 22 749 09 47copyrightiso.orgww
8、w.iso.orgBS ISO 14242-2:2016ISO 14242-2:2016(E)Foreword iv1 Scope . 12 Normative reference . 13 Terms and definitions . 14 Gravimetric method 14.1 Principle 14.2 Reagents and materials . 14.3 Apparatus 24.4 Preparation of test specimen for gravimetric measurements . 24.5 Procedure for gravimetric me
9、asurement. 35 Dimensional change method . 35.1 Principle 35.2 Apparatus 35.3 Procedure for dimensional change measurement . 46 Test report . 4 ISO 2016 All rights reserved iiiContents PageBS ISO 14242-2:2016ISO 14242-2:2016(E)ForewordISO (the International Organization for Standardization) is a worl
10、dwide 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
11、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 do
12、cument 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 documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Direct
13、ives, 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 shall not be held responsible for identifying any or all such patent rights. Details of any patent rights identified during the developm
14、ent 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 document is information given for the convenience of users and does not constitute an endorsement.For an explanation on the meaning of ISO spec
15、ific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary informationThe committee responsible for this document is ISO/TC 150, Implants for s
16、urgery, Subcommittee SC 4, Bone and joint replacements.This second edition cancels and replaces the first edition (ISO 14242-2:2000), of which it constitutes a minor revision.ISO 14242 consists of the following parts, under the general title Implants for surgery Wear of total hip-joint prostheses: P
17、art 1: Loading and displacement parameters for wear-testing machines and corresponding environmental conditions for test Part 2: Methods of measurement Part 3: Loading and displacement parameters for orbital bearing type wear testing machines and corresponding environmental conditions for testiv ISO
18、 2016 All rights reservedBS ISO 14242-2:2016INTERNATIONAL STANDARD ISO 14242-2:2016(E)Implants for surgery Wear of total hip-joint prostheses Part 2: Methods of measurement1 ScopeThis part of ISO 14242 specifies methods of assessment of wear of the acetabular component of total hip-joint prostheses
19、using gravimetric techniques and changes in dimensional form of components tested in accordance with ISO 14242-1 or ISO 14242-3 as appropriate.NOTE Some investigators have experienced problems with organic deposits affecting the results of measurements, especially with hard/hard combinations. No spe
20、cific precautions are included in this part of ISO 14242, but cleaning techniques adopted is intended to be suitable for the soils produced.2 Normative referenceThe following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For da
21、ted references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.ISO 14242-1, Implants for surgery Wear of total hip-joint prostheses Part 1: Loading and displacement parameters for wear-testing machines and corr
22、esponding environmental conditions for testISO 14242-3, Implants for surgery Wear of total hip-joint prostheses Part 3: Loading and displacement parameters for orbital bearing type wear testing machines and corresponding environmental conditions for test3 Terms and definitionsFor the purposes of thi
23、s document, the following terms and definitions apply.3.1wearmaterial loss from components of the prosthetic joint due to combined movement and loading4 Gravimetric method4.1 PrincipleThe test specimen is soaked in a lubricant. It is repeatedly removed from the lubricant, cleaned, dried and weighed
24、until a steady rate of fluid sorption is established. The test specimen is assessed subsequently for wear by testing for loss in mass in a knee-hip simulator. A loaded, non-articulating control specimen is intended to allow for fluid sorption and undergoes the same procedure for reference purposes.4
25、.2 Reagents and materials4.2.1 Fluid test medium, in accordance with ISO 14242-1 or ISO 14242-3 as appropriate. ISO 2016 All rights reserved 1BS ISO 14242-2:2016ISO 14242-2:2016(E)4.2.2 Control specimen, in accordance with ISO 14242-1 or ISO 14242-3 as appropriate.4.2.3 Propan-2-ol.4.3 Apparatus4.3.
26、1 Balance, with an accuracy of 0,1 mg, of sufficient capacity for the mass of the test specimen.4.3.2 Ultrasonic cleaner.4.3.3 Vacuum drying system, capable of achieving a vacuum of at least 13,33 Pa.4.3.4 Filtered inert-gas jet, e.g. nitrogen.4.4 Preparation of test specimen for gravimetric measure
27、ments4.4.1 Soak the test specimen and control specimen in the fluid test medium (4.2.1) for 48 h 4 h.4.4.2 Remove the test specimen and control specimen from the fluid test medium (4.2.1) and clean in the ultrasonic cleaner (4.3.2).A typical cleaning regime in the ultrasonic cleaner is as follows:a)
28、 vibrate for 10 min in deionized water;b) rinse in deionized water;c) vibrate for 10 min in a mixture of ultrasonic cleaning detergent in deionized water at the concentration recommended by the detergent manufacturer;d) rinse in deionized water;e) vibrate for 10 min in deionized water;f) rinse in de
29、ionized water;g) vibrate for 3 min in deionized water;h) rinse in deionized water;i) dry in a vacuum drying chamber (4.3.3).Care should be taken to avoid abrasion in the ultrasonic cleaner which could lead to change in mass.4.4.3 Dry the test specimen and control specimen with a jet of filtered iner
30、t gas (4.3.4).4.4.4 Soak the test specimen and control specimen in propan-2-ol (4.2.3) for 5 min 15 s.4.4.5 Dry the test specimen and control specimen with a jet of filtered inert gas (4.3.4), then dry further in a vacuum of better than 13,3 Pa 0,13 Pa for at least 30 min.4.4.6 Weigh the test specim
31、en and control specimen on the balance twice in rotation within 90 min of removal from the vacuum. If the two readings per specimen are not identical within 0,1 mg, continue taking readings in rotation until at least two readings per specimen are identical within 0,1 mg. Store the test specimen and
32、control specimen in a sealed dust-free container between weighings.2 ISO 2016 All rights reservedBS ISO 14242-2:2016ISO 14242-2:2016(E)4.4.7 Repeat 4.4.2 to 4.4.6 at intervals until the incremental mass change of the specimen over 24 h is less than 10 % of the previous cumulative mass change.4.4.8 R
33、ecord the average increase in mass S of the control specimen.4.5 Procedure for gravimetric measurement4.5.1 Mount the test pieces in the testing machine and conduct the wear test in accordance with ISO 14242-1 or ISO 14242-3 as appropriate.4.5.2 Record the mass of the specimens.4.5.3 On each occasio
34、n when the test specimen and control specimen are removed from the wear-testing machine, repeat the procedures 4.4.2 to 4.4.6, 4.5.1 and 4.5.2.4.5.4 Calculate the gravimetric wear as shown in Formula (1):Wn= Wan+ Sn(1)whereWnis the net mass loss after n cycles of loading;Wanis the average uncorrecte
35、d mass loss;Snis the average increase in mass of the control specimen over the same period.4.5.5 Calculate the average wear rate aGusing Formula (2) for the least squares linear fit relationship between Wnand the number of loading cycles n:Wn= aG n + b (2)where Wnis the net loss in mass after n cycl
36、es and b is a constant.The zero time point shall not be used in this calculation.5 Dimensional change method5.1 PrincipleA coordinate measuring machine is used to map the articulating surface of a total hip prosthesis relative to a reference position, direction and plane prior to the start of the we
37、ar test and at suitable intervals during the test. From these data, the volumetric change between measurements is determined. Loaded non-articulating controls are intended to allow the effects of plastic flow, mainly occurring in the first 5 105cycles, to be separated from material loss.5.2 Apparatu
38、s5.2.1 Three-dimensional coordinate measuring machine, with maximum axial-position error of measurement D, in micrometres, of:D = 4 + 4l 106(3)where l is the numerical value of the dimension, expressed in metres. ISO 2016 All rights reserved 3BS ISO 14242-2:2016ISO 14242-2:2016(E)5.2.2 Ultrasonic cl
39、eaner.5.3 Procedure for dimensional change measurement5.3.1 Select a point of reference, an origin and a plane on the test specimen. Maintain this reference system throughout the procedure.5.3.2 Clean the specimens.5.3.3 To ensure dimensional stability, retain the test specimen at the measurement te
40、mperature 2 C (measured at the normal points of the metrology laboratory) for at least 48 h.5.3.4 At the beginning of a series of tests, check that relocation of the test specimen does not affect the measured volume by more than 0,05 %.This may be achieved by the use of fixturing or the recognition
41、of features in software, for example.5.3.5 Start the measurement machine and produce a full three-dimensional contour mesh of the articulating surface of the test specimen. Ensure the mesh spacing is no greater than 1 mm in the horizontal plane or along any arc.5.3.6 Calculate the volume Vnof the ac
42、etabular cavity, where n is the number of wear cycles which have been applied.5.3.7 Express the wear as the volume change after n loading cycles, Vn, as shown in Formula (4):Vn= Vn Vo(4)where Vois the original volume.5.3.8 Insert the test specimen and any control specimen in the testing machine and
43、conduct the tests in accordance with ISO 14242-1 or ISO 14242-3 as appropriate.5.3.9 On each occasion when the test specimen and the control specimen are removed from the testing machine, repeat procedures 5.3.2 to 5.3.7.5.3.10 Calculate the wear rate, aV, using Formula (5) for the least squares lin
44、ear relationship between Vnand n as:Vn= aV n + b (5)where b is a constant, using a least squares fit.When controls are provided, the slope of the line, representing the rate of creep, should be calculated including the zero time point. The zero time point shall not be used in the slope calculation f
45、or the wear rate aV.6 Test reportThe test report shall include the following information:a) a reference to this part of ISO 14242, i.e. ISO 14242-2;b) the identity of the test specimens, as stated by the party submitting the specimen for test;4 ISO 2016 All rights reservedBS ISO 14242-2:2016ISO 1424
46、2-2:2016(E)c) the method of wear measurement (i.e. gravimetric or dimensional change);d) the value Wnfor each measurement using the gravimetric method, or the value Vnfor each measurement using the dimensional change method;e) the wear rate, aGor aV(gravimetric or dimensional change method);f) a ref
47、erence to the wear test method used from ISO 14242-1 or ISO 14242-3 as appropriate. ISO 2016 All rights reserved 5BS ISO 14242-2:2016ISO 14242-2:2016(E) ISO 2016 All rights reservedICS 11.040.40Price based on 5 pagesThis page deliberately left blankBSI is the national body responsible for preparing
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