ASTM_F_2979_-_14.pdf

Designation:F297914Standard Guide forCharacterization of Wear from the Articulating Surfaces inRetrieved Metal-on-Metal and other Hard-on-Hard HipProstheses1This standard is issued under the fixed designation F2979;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This guide specifies a method to measure the in-vivowear of explanted Metal-on-Metal(MoM)and other“hard”(e.g.,ceramic)hip components.The guide covers the measure-ment of acetabular cups and femoral heads using a dimensionalchange method and is applicable to all prosthetic hip types,including stemmed(modular)and resurfacing hip systems.1.2 The methods specified in this guide are not applicablefor measuring the in-vivo wear from non-articulating surfaces,for example modular connections(at the stem/neck,neck/heador cup liner/shell interface)or at acetabular cup rim.1.3 The parameters(wear depth and volumetric wear)evaluated and reported in this guide are estimated from theassumed as-manufactured shape of the components.The wearvolume is calculated using a numerical integration method andthe wear depth is the difference between the assumed as-manufactured shape and the measured surface.1.4 This guide covers the measurement of the depth of wearand the volumetric wear using a Coordinate Measuring Ma-chine(CMM)and the depth of wear using an RoundnessMachine.Other metrology measurement equipment may beused to measure the wear depth or volume if the resolution andaccuracy of the measurements are comparable with the instru-ments detailed in this standard.The measurement and analysisprotocols should be based on those described in this standard.1.5 This guide is applicable to hip joints which are nomi-nally spherical at the time of manufacture.Form deviationsresulting from manufacturing or deformation may occur andmay necessitate the use of a non-spherical surface to representthe unworn surface of the component.Hip joints designed withasymmetry are considered beyond the scope of this guide,although the principles and techniques may be applicable to thecharacterization of wear from the articulating surfaces.1.6 This guide is intended as an extension toASTM F561 asa Stage II nondestructive test.1.7 This standard may involve hazardous materials,opera-tions and equipment.As a precautionary measure,explanteddevices should be sterilized or disinfected by an appropriatemeans that does not adversely affect the implant or theassociated tissue that may be the subject of subsequentanalysis.A detailed discussion of precautions to be used inhandling human tissues can be found in ISO 12891-1.Thisstandard does not purport to address all of the safety concerns,if any,associated with its use.It is the responsibility of the userof this standard to establish appropriate safety and healthpractices and determine the applicability of regulatory limita-tions prior to use.2.Referenced Documents2.1 ASTM Standards:2F561 Practice for Retrieval and Analysis of MedicalDevices,and Associated Tissues and FluidsF2033 Specification for Total Hip Joint Prosthesis and HipEndoprosthesis Bearing Surfaces Made of Metallic,Ceramic,and Polymeric Materials2.2 ISO Standard:3ISO 12181-1-2003 Part 1 Geometrical product specifica-tions roundness,vocabulary and parameters of roundness3.Terminology3.1 Definitions:3.1.1 For the purposes of this standard the following defi-nitions shall apply.3.1.2 cup rimthe circle formed by the intersection of thearticulating surface and the plane normal to the revolution axisthat lies coincident with the extreme point of the open cup face.1This test method is under the jurisdiction ofASTM Committee F04 on Medicaland Surgical Materials and Devices and is the direct responsibility of SubcommitteeF04.22 on Arthroplasty.Current edition approved Feb.1,2014.Published April 2014.DOI:10.1520/F2979-14.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3Available from American National Standards Institute(ANSI),25 W.43rd St.,4th Floor,New York,NY 10036,http:/www.ansi.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.1.3 edge wearthe pattern of wear observed in acetabularcups in which the maximum wear depth occurs at the cup rimand progressively deceases along a path from the cup rim to thepole(1-3).43.1.4 equator of the articulating surfacethe equator of thearticulating surface is the circle normal to the revolution axis ofthe component and to the spherical articulating surface.3.1.5 form deviationsdeviations from the nominal de-signed spherical shape of the hip implants that are not the