1、Designation: F 1875 98 (Reapproved 2004)Standard Practice forFretting Corrosion Testing of Modular Implant Interfaces:Hip Femoral Head-Bore and Cone Taper Interface1This standard is issued under the fixed designation F 1875; the number immediately following the designation indicates the year oforigi
2、nal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice describes the testing, analytical, and char-acter
3、ization methods for evaluating the mechanical stability ofthe bore and cone interface of the head and stem junction ofmodular hip implants subjected to cyclic loading by measure-ments of fretting corrosion (1-5).2Two test methods describedare as follows:1.1.1 Method IThe primary purpose of this meth
4、od is toprovide a uniform set of guidelines for long-term testing todetermine the amount of damage by measurement of theproduction of corrosion products and particulate debris fromfretting and fretting corrosion. Damage also is assessed bycharacterization of the damage to the bore and cone surfaces(
5、4, 5).1.1.2 Methods IIThis method provides for short-termelectrochemical evaluation of the fretting corrosion of themodular interface. It is not the intent of this method to producedamage nor particulate debris but rather to provide a rapidmethod for qualitative assessment of design changes which do
6、not include material changes (1-4).1.2 This practice does not provide for judgment or predic-tion of in vivo implant performance, but rather, provides for auniform set of guidelines for evaluating relative differences inperformance between differing implant designs, constructs, ormaterials with perf
7、ormance defined in the context of theamount of fretting and fretting corrosion. Also, this practiceshould permit direct comparison of fretting corrosion databetween independent research groups, and thus, provide forbuilding of a data base on modular implant performance.1.3 This practice provides for
8、 comparative testing of manu-factured hip femoral heads and stems and for coupon typespecimen testing where the male taper portion of the modularjunction does not include the entire hip implant, with the taperportion of the coupon identical in design, manufacturing, andmaterials to the taper of the
9、final hip implant (4,5).1.4 Method I of this practice has been provided in a mannerto permit simultaneous evaluation of the fatigue strength of afemoral hip stem (in accordance with Practice F 1440) and themechanical stability and debris generated by fretting andfretting corrosion of the modular int
10、erface.1.5 The general concepts and methodologies described inthis practice could be applied to the study of other modularinterfaces in total joint prostheses.1.6 This standard may involve hazardous materials, opera-tions, and equipment. This standard does not purport toaddress all of the safety con
11、cerns, if any, associated with itsuse. It is the responsibility of the user of this standard toestablish appropriate safety and health practices and deter-mine the applicability of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:3E 4 Practices for Force Verification of
12、Testing MachinesE 466 Practice for Conducting Force Controlled ConstantAmplitude Axial Fatigue Tests of Metallic MaterialsE 467 Practice for Verification of Constant Amplitude Dy-namic Loads in an Axial Load Fatigue Testing MachineF 561 Practice for Retrieval and Analysis of ImplantedMedical Devices
13、 and Associated TissuesF 746 Test Method for Pitting or Crevice Corrosion ofMetallic Surgical Implant MaterialsF 897 Test Method for Measuring Fretting Corrosion ofOsteosynthesis Plates and ScrewsF 1440 Practice for Cyclic Fatigue Testing of MetallicStemmed Hip Arthroplasty Femoral Components Withou
14、tTorsionF 1636 Specification for Bores and Cones for ModularFemoral Heads4G 3 Practice for Conventions Applicable to ElectrochemicalMeasurements in Corrosion TestingG 5 Reference Test Method for Making Potentiostatic andPotentiodynamic Anodic Polarization Measurements1This practice is under the juri
15、sdiction of ASTM Committee F04 on Medical andSurgical Materials and Devices and is the direct responsibility of SubcommitteeF04.15 on Material Test Methods.Current edition approved Aug. 1, 2004. Published August 2004. Originallyapproved in 1998. Last previous edition approved in 1998 as F 1875 98.2T
16、he bold face numbers in parentheses refers to the list of references at the endof this standard.3For 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 Docume
17、nt Summary page onthe ASTM website.4Withdrawn.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.G 15 Terminology Relating to Corrosion and CorrosionTestingG 40 Terminology Relating to Wear and ErosionG 61 Test Method for Conducting Cyc
18、lic PotentiodynamicPolarization Measurements for Localized Corrosion Sus-ceptibility of Iron-, Nickel-, or Cobalt-Based AlloysG 102 Practice for Calculation of Corrosion Rates andRelated Information from Electrochemical Measurements2.2 ISO Standards:ISO 7206-7 Endurance Performance of Stemmed Femora
19、lComponents Without Application of Torsion53. Terminology3.1 Definitions:3.1.1 corrosive wear, nwear in which chemical or elec-trochemical reaction with the environment is significant.3.1.2 coverage, nthe length, parallel to the taper surface,that the bore and cone interfaces are in contact.3.1.3 cr
20、evice corrosion, nlocalized corrosion of a metalsurface at, or immediately adjacent to, an area that is shieldedfrom full exposure to the environment because of closeproximity between the metal and the surface of anothermaterial.3.1.4 external circuit, nthe wires, connectors, measuringdevices, curre
21、nt sources, and so forth that are used to bringabout or measure the desired electrical conditions within thetest cell.3.1.5 femoral head neck extension, na distance parallel tothe taper axis, from the nominal neck offset length (k)asdefined in Specification F 1636, and the center of the head.Such va
22、riants from the nominal length are used to adjust forresection level, leg length, and so forth. A positive neckextension equates to the center of the head being locatedfurther away from the stem.3.1.6 fretting, nsmall amplitude oscillatory motion, usu-ally tangential, between two solid surfaces in c
23、ontact.3.1.7 fretting corrosion, nthe deterioration at the interfacebetween contacting surfaces as the result of corrosion andslight oscillatory slip between the two surfaces.3.1.8 fretting wear, nwear arising as a result of fretting.3.1.9 total elemental level, nthe total weight of particulatematte
24、r and corrosion ions generated by fretting wear andfretting corrosion. Most analytical techniques are unable toaccurately differentiate between ions and particulates, andtherefore, total elemental level refers to all matter and corro-sion products released by fretting wear and corrosion.3.1.10 wear,
25、 ndamage to a solid surface, generally in-volving progressive loss of material, due to relative motionbetween that surface and a contacting substance or substances.4. Summary of Test Method4.1 Method IThe femoral stem and head components, orcoupons to simulate head-taper-neck geometry, are loadedcyc
26、lically in a manner similar to that described in PracticeF 1440. The head neck junction is exposed to a saline orproteinaceous solution, either by immersion of the entiredevice, or with a fluid containing envelope. The cyclic load isapplied for a minimum of 10 million cycles. At the conclusionof tes
27、ting, the isolated fluid is withdrawn for chemical analysisfor total elemental level, and characterization of particulatedebris. The taper interface is subsequently disengaged and thesurfaces inspected for fretting wear and corrosion using opticalmicroscopy and scanning electron microscopy. The outp
28、ut ofthese methods is a quantitative measure of total elemental leveland a qualitative evaluation of damage of the modular interfacecaused by fretting wear and corrosion.4.2 Method IIA coupon similar to that used in Method I,or an entire femoral stem and head construct, may be mountedin an inverted
29、position in a test chamber. The chamber is filledwith an electrolyte solution to a level sufficient to submerge thebore and cone interface and a small portion of the exposedneck. The area of contact and articulation between the ball andthe test apparatus is isolated from the electrolyte, either bybe
30、ing above the fill level, or with an elastomeric seal used toisolate the bottom of the test chamber.4.2.1 Procedure AA saturated calomel electrode with aluggin probe is used as a reference electrode to measurechanges in the corrosion potential with an electrometer. Acounter electrode also may be emp
31、loyed and the polarizationcharacteristics measured with a potentiostat.4.2.2 Procedure BA large surface area counter electrodeis immersed in the solution to simulate the area of the stem. Azero-resistance ammeter is connected between the test deviceand the counter electrode. The difference in curren
32、t, thusmeasured prior to and during cyclic loading, represents thefretting corrosion current flowing between the modular inter-face (anode) and the metal sheet (cathode).5. Significance and Use5.1 The modular interfaces of total joint prostheses aresubjected to micromotion that could result in frett
33、ing andcorrosion. The release of corrosion products and particulatedebris could stimulate adverse biological reactions, as well aslead to accelerated wear at the articulation interface. Methodsto assess the stability and corrosion resistance of the modularinterfaces, therefore, are an essential comp
34、onent of devicetesting.5.2 Long-term in vitro testing is essential to produce dam-age and debris from fretting of a modular interface (4,5). Theuse of proteinaceous solutions is recommended to best simulatethe in vivo environment.5.3 Short-term tests often can be useful in evaluations ofdifferences
35、in design during device development (1-4). Theelectrochemical methods provide semiquantitative measures offretting corrosion rates. The relative contributions of mechani-cal and electrochemical processes to the total corrosion andparticulate release phenomena, however, have not been estab-lished; th
36、erefore, these tests should not be utilized to comparethe effects of changes in material combinations, but rather beutilized to evaluate design changes of bore (head) and cone(stem) components.5.4 These tests are recommended for evaluating the frettingwear and corrosion of modular interfaces of hip
37、femoral head5Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036.F 1875 98 (2004)2and stem components. Similar methods may be applied to othermodular interfaces where fretting corrosion is of concern.5.5 These methods are recommended for comparat
38、iveevaluation of the fretting wear and corrosion of new materials,coatings, or designs, or a combination thereof, under consid-eration for hip femoral head and neck modular interfaces.Components for testing may be those of a manufacturedmodular hip device (finished product) or sample coupons,which a
39、re designed and manufactured for simulation of thehead, taper, and neck region of a modular hip device.6. Apparatus6.1 Testing MachinesThe action of the machine should beanalyzed to ensure that the desired form and periodic forceamplitude is maintained for the duration of the test (seePractice E 467
40、). The test machine should have a load monitor-ing system, such as the transducer mounted in line with thespecimen. The loads should be monitored continuously in theearly stages of the test and periodically thereafter to ensure thedesired load cycle is maintained. The varying load as deter-mined by
41、suitable dynamic verification should be maintained atall times to within 62 % of the maximum force being used inaccordance with Practices E 4 and E 466.6.2 Specimen Mounting Devices, Method IModular hipand stem components shall be set-up as described in PracticesF 1440. Coupon samples shall be set-u
42、p as shown in Fig. 1.The set-up must provide for identical loading geometry as thatin Practice F 1440.6.3 Specimen Mounting Devices, Method IIModular hipand stem components shall be set-up in an inverted position, asshown in Fig. 2. Coupon samples may be set up as shown inFig. 1, or in an inverted o
43、rientation.6.4 Environmental Containment, Method IThe prosthesismay be placed in an environmental chamber, which is filledwith the appropriate fluid. Care should be taken to ensure thatthe contact area between the head and the low friction thrustbearing is not exposed to the electrolyte solution. Th
44、e modularinterface of the prostheses or coupon samples also may beenclosed in an elastomeric sleeve, which contains the electro-lyte. The materials used for such isolation must be nonreactiveand capable of retaining the fluid environment, (that is, preventleakage), throughout the course of testing.
45、The volume of thechamber shall be between 5 and 100 mL.NOTE 1The use of small fluid volumes with the sleeve containmentmethod may not produce as much fretting corrosion as full prosthesisexposure, due to the reduced surface area of the cathodic metal exposed.6.5 Environmental Chamber, Method IIThe c
46、hamber shallbe filled with electrolyte so as to submerge the modularinterface. An elastomeric seal is used to isolate the contact areabetween the head and the load application surface. Similarseals should be employed for coupon sample testing. Forcoupons orientated shown in Fig. 1, the chamber fill
47、level shallbe kept below the articulation between the head and the loadingapparatus.6.6 Counter and Reference Electrodes, Method IIAcounter electrode is included in the external circuit of MethodII to act as a cathode for measurement of corrosion currents. Areference electrode is employed for measur
48、ement of thecorrosion potential of the specimen.6.6.1 Method II, Procedure AThe counter electrode andsaturated calomel electrode (SCE) shall be employed in accor-dance with Test Methods G 5 and G 61.6.6.2 Method II, Procedure BThe counter electrode isused to simulate the surface area of the femoral
49、stem. It shouldbe made of the same alloy as the stem material being tested. Asurface area at least equal to the stem and any porous coatingshould be employed. An area of 400 cm2is recommended. Thecounter electrode should not be in contact with the testspecimen, but rather is connected to it via the zero resistanceammeter.6.7 Potential and Current Measuring Equipment, Method II,Procedure AThe potential shall be measured by a highimpedance voltmeter. This could either be a free standingelectrometer with an impedance 1010V, or the electrometer ina potentiostat
