1、BS ISO12189:2008ICS 11.040.40NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDImplants for surgery Mechanical testingof implantable spinaldevices Fatiguetest method for spinalimplant assembliesusing an anteriorsupportLicensed Copy: Wang Bin, ISO/EXCHANGE CHINA ST
2、ANDARDS, 28/10/2009 02:56, Uncontrolled Copy, (c) BSIThis British Standardwas published under theauthority of the StandardsPolicy and StrategyCommittee on 28 February2009 BSI 2009ISBN 978 0 580 63685 1Amendments/corrigenda issued since publicationDate CommentsBS ISO 12189:2008National forewordThis B
3、ritish Standard is the UK implementation of ISO 12189:2008.The UK participation in its preparation was entrusted to TechnicalCommittee CH/150/5, Osteosynthesis and spinal devices.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does no
4、t purport to include all the necessary provisionsof a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunityfrom legal obligations.Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 28/10/2009 02:56, Uncontrolled Copy, (c) BSIBS ISO
5、12189:2008Reference numberISO 12189:2008(E)ISO 2008INTERNATIONAL STANDARD ISO12189First edition2008-05-01Implants for surgery Mechanical testing of implantable spinal devices Fatigue test method for spinal implant assemblies using an anterior support Implants chirurgicaux Essais mcaniques des dispos
6、itifs spinaux implantables Mthode dessai de fatigue des ensembles dimplants spinaux utilisant un support antrieur Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 28/10/2009 02:56, Uncontrolled Copy, (c) BSIBS ISO 12189:2008ISO 12189:2008(E) PDF disclaimer This PDF file may contain embedded ty
7、pefaces. In accordance with Adobes licensing policy, this file may be printed or viewed but shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In downloading this file, parties accept therein the responsibility of not inf
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9、timized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below. COPYRIGHT PROTECTED DOCUMENT ISO 2008 All rights reserved.
10、 Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISOs member body in the country of the requester.
11、ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO 2008 All rights reservedLicensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 28/10/2009 02:56, Uncontrolled Copy, (c) BSIBS IS
12、O 12189:2008ISO 12189:2008(E) ISO 2008 All rights reserved iiiContents Page Foreword iv Introduction v 1 Scope . 1 2 Normative references . 1 3 Terms and definitions. 1 4 Principle. 2 5 Reagents and materials . 3 5.1 Fluid test medium (optional) 3 5.2 Test specimen . 4 6 Apparatus 8 6.1 Testing mach
13、ine 8 6.2 Means of mounting and enclosing the test specimen 8 6.3 Temperature control system (optional) 8 7 Procedure 8 8 Test report . 9 9 Accuracy and bias 10 9.1 Accuracy 10 9.2 Bias. 10 Bibliography . 11 Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 28/10/2009 02:56, Uncontrolled Copy,
14、(c) BSIBS ISO 12189:2008ISO 12189:2008(E) iv ISO 2008 All rights reservedForeword 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 tec
15、hnical 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 closel
16、y with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft
17、International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this documen
18、t may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 12189 was prepared by Technical Committee ISO/TC 150, Implants for surgery, Subcommittee SC 5, Osteosynthesis and spinal devices. Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA ST
19、ANDARDS, 28/10/2009 02:56, Uncontrolled Copy, (c) BSIBS ISO 12189:2008ISO 12189:2008(E) ISO 2008 All rights reserved vIntroduction Different concepts of posterior spinal fusion devices such as “rigid” and “semi-rigid” or “dynamic” systems are available on the market. Some of these existing spinal im
20、plants are not indicated in major instability cases (“semi-rigid” or “dynamic” implants, hook- and wire-based fixation implants, artificial ligaments, etc.), because they have been designed to allow load-sharing with the anterior column. This document strongly emphasises the effects of the load-shar
21、ing phenomenon, largely described in the literature, as a very important feature regarding the load patterns to which the spinal implants are submitted. As these different concepts result in different implant behaviour, a corpectomy configuration construct might not always be appropriate for testing
22、, since total corpectomy without subsequent provision for anterior support occurs very seldom in clinical practice, and also because this kind of construct neglects the influence of anterior column support on implant loading. Moreover, some kinds of implant are often too flexible to be tested on the
23、ir own or in a corpectomy configuration. This International Standard is intended to allow fatigue testing of flexible spinal implants and allow biomechanical fatigue testing of any kind of spinal implants, particularly semi-rigid and dynamic implants, regardless of their intrinsic rigidity. This doc
24、ument describes compression/flexion fatigue testing; additional mechanical tests, such as multi-directional testing (shear, torsion, lateral bending), might be required to assess clinical device safety. For devices which are able to withstand loading in a corpectomy configuration, the test should be
25、 performed without anterior support in accordance with ASTM F1717 to demonstrate that, in a worst-case scenario, the device can support full load. This International Standard is related to the methods for fatigue test of spinal implant assemblies (for fusion or motion preservation) with an anterior
26、support. Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 28/10/2009 02:56, Uncontrolled Copy, (c) BSIBS ISO 12189:2008Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 28/10/2009 02:56, Uncontrolled Copy, (c) BSIBS ISO 12189:2008INTERNATIONAL STANDARD ISO 12189:2008(E) ISO 2008 All right
27、s reserved 1Implants for surgery Mechanical testing of implantable spinal devices Fatigue test method for spinal implant assemblies using an anterior support 1 Scope This International Standard specifies methods for fatigue testing of spinal implant assemblies (for fusion or motion preservation) usi
28、ng an anterior support. It is intended to provide a basis for the assessment of intrinsic static and dynamic strength of spinal implants. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited app
29、lies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 10243, Tools for pressing Compression springs with rectangular section Housing dimensions and colour coding ASTM F1717, Standard Test Methods for Spinal Implant Constructs in a Vertebr
30、ectomy Model 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 active length of the longitudinal element straight line distance between the centre of attachment of the superior anchor and the centre of attachment of the inferior anchor 3.2 mode
31、l moment arm perpendicular distance to the applied load between the insertion point of an anchor and the load application centre 3.3 failure permanent deformation resulting from fracture; plastic deformation or loosening beyond the ultimate displacement that would render the spinal implant assembly
32、ineffective or unable to adequately resist load 3.4 insertion point of an anchor location where the anchor is attached to the segment model Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 28/10/2009 02:56, Uncontrolled Copy, (c) BSIBS ISO 12189:2008ISO 12189:2008(E) 2 ISO 2008 All rights rese
33、rved3.5 intended spinal location anatomic region of the spine intended for the application of the spinal implant assembly NOTE Spinal implant assemblies are developed for specific spinal locations such as the anterior cervical spine or the posterior cervical, thoraculumbar, lumbar and lumbosacral sp
34、ine. 3.6 maximum run-out load maximum load that can be applied to a spinal implant assembly where all of the tested constructs have withstood 5 000 000 cycles without a failure 3.7 spinal implant assembly complete spinal implant configuration as intended for surgical use NOTE A spinal implant assemb
35、ly will contain anchors, interconnections and longitudinal elements and can contain transverse elements. 3.8 spinal implant construct complete spinal implant assembly attached to the appropriate test support 3.9 UHMWPE test block component of the test apparatus for mounting the spinal implant assemb
36、ly NOTE 1 A specific design of UHMWPE test blocks is required for each intended spinal location and intended method of application. Figures 1, 2 and 3 describe the recommended designs for the test blocks (lumbar samples) and Figure 4 describes the recommended design for cervical samples; however, al
37、ternate designs can be used as long as equivalent performance is demonstrated. NOTE 2 Spinal implant assemblies contain different types of anchors. Each type of anchor has an intended method of application to the spine. 4 Principle The aim of this International Standard is to provide a fatigue test
38、method that allows for testing of spinal devices that are not suited to corpectomy testing. This protocol is based on the use of modified Ultra-High Molecular Weight Polyethylene (UHMWPE) test blocks (derived from those used in corpectomy or corporectomy testing) and springs (see Figure 1). This tes
39、t support is composed of test blocks, made of UHMWPE representing vertebrae, and standardized springs representing the intervertebral disc stiffness. The springs are chosen from the “standardized” panel offered by ISO 10243. Then, fatigue tests in flexion compression are performed on the spinal impl
40、ant construct (see Figure 1) in order to evaluate the spinal implant assembly (fatigue testing). The insertion points shown in Figure 1 should be adhered to if possible. In situations where the design of the spinal implant assembly or the manufacturers surgical instructions for installation dictate
41、otherwise, the attachment points may deviate from these dimensions. Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 28/10/2009 02:56, Uncontrolled Copy, (c) BSIBS ISO 12189:2008ISO 12189:2008(E) ISO 2008 All rights reserved 3Dimensions in millimetres Key 1 insertion points aLoad. Figure 1 A s
42、tandard lumbar bilateral construct containing rods and screws 5 Reagents and materials 5.1 Fluid test medium (optional) The use of a simulated body fluid, saline (9 g NaCl per 1 000 ml water), may be considered. In this case, it is necessary (before the fatigue test) to introduce the fluid test medi
43、um to completely immerse the contact surfaces of the test spinal implant construct. The temperature of the fluid test medium should be maintained at 37 C 2 C, and measurements during the tests should be taken at a location representative of the bulk temperature of the fluid. Licensed Copy: Wang Bin,
44、 ISO/EXCHANGE CHINA STANDARDS, 28/10/2009 02:56, Uncontrolled Copy, (c) BSIBS ISO 12189:2008ISO 12189:2008(E) 4 ISO 2008 All rights reservedNOTE In case of use of a simulated body fluid, and as ISO 10243 does not define the specific material properties of the springs, particular attention should be
45、given to protecting the springs from corrosive agents, or to the use of springs (or alternative elastic elements, as long as the static and fatigue features are appropriate) made of corrosion-resistant materials. 5.2 Test specimen The test support is implemented with UHMWPE test blocks and springs m
46、anufactured in accordance with ISO 10243 relative to housing dimensions and colour coding of compression springs with rectangular section, which define standardized stiffness of these springs. Springs are inserted between UHMWPE test blocks thanks to cylindrical reaming performed on each UHMWPE test
47、 block (see Figures 2 and 3). To preserve the spacing recommended in ASTM F1717 between UHMWPE test blocks (76 mm for lumbar implants and 35 mm for cervical implants), three blocks are considered for lumbar implants and two blocks for cervical implants. Alternative designs of the test support may be
48、 used as long as justification is provided. For example, a mono-segmental test set-up could be considered with a screw distance of 38 mm for lumbar implants. The UHMWPE used to manufacture the tests blocks should have a tensile breaking strength equal to 40 MPa 3 MPa. To be consistent with the physi
49、ological behaviour of lumbar discs under compression loads, it is recommended that a combination of three springs in the same plane be used (see Figure 1). Each spring should have a spring stiffness of 375 N/mm with L0= 25 mm and ext= 25 mm. NOTE 1 The stiffness under compression of the lumbar disc is roughly estimated in the literature to be between 700 N/mm and 2 500 N/mm (see References 1 to 4). NOTE 2 A spring with a stiffness of 375 N/mm that complies with ISO 10243 is colour-coded red. For cervical implants (
