1、Designation: F3047M 15Standard Guide forHigh Demand Hip Simulator Wear Testing of Hard-on-hardArticulations1This standard is issued under the fixed designation F3047M; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of las
2、t 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 The objective of this guide is to advise researchers onthe possible high demand wear test features that should beincluded
3、 in evaluation of hard on hard articulations. This guidemakes suggestions of what high demand test features may needto be added to an overall high demand wear test regime. Devicearticulating components manufactured from other metallicalloys, ceramics or with coated or elementally modified sur-faces
4、could possibly be evaluated with this guide. Howeversuch materials may include risks and failure mechanismswhich are not adressed in this guide.1.2 Hard-on-hard hip bearing systems include metal-on-metal, ceramic-on-ceramic, ceramic-on-metal, or any otherbearing systems where both the head and cup c
5、omponents havehigh surface hardness. An argument has been made that thehard-on-hard THR articulation may be better for younger moreactive patients. These younger patients may be more physicallyfit and expect to be able to perform more energetic activities.Consequently, new designs of hard-on-hard TH
6、R articulationsmay have some implantations subjected to more demandingand longer wear performance requirements.1.3 Total Hip Replacement (THR) with metal-on-metalarticulations have been used clinically for more than 50 years(1, 2).2Early designs had mixed clinical results. Eventuallythey were eclips
7、ed by THR systems using metal on polyeth-ylene articulations. In the 1990s the metal-on-metal articula-tion again became popular with more modern designs (3),including surface replacement.1.4 In the 1970s the first ceramic-on-ceramic THR articu-lations were used. In general, the early results were n
8、otsatisfactory (4, 5). Improvement in alumina, and new designsin the 1990s improved the results for ceramic-on-ceramicarticulations (6).1.5 The values stated in SI units are to be regarded as thestandard.1.6 This standard does not purport to address all of thesafety concerns, if any, associated with
9、 its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:3F75 Specification for Cobalt-28 Chromium-6 MolybdenumAlloy Castings
10、and Casting Alloy for Surgical Implants(UNS R30075)F86 Practice for Surface Preparation and Marking of Metal-lic Surgical ImplantsF799 Specification for Cobalt-28Chromium-6MolybdenumAlloy Forgings for Surgical Implants (UNS R31537,R31538, R31539)F1537 Specification for Wrought Cobalt-28Chromium-6Mol
11、ybdenum Alloys for Surgical Implants (UNSR31537, UNS R31538, and UNS R31539)F1814 Guide for Evaluating Modular Hip and Knee JointComponentsF1820 Test Method for Determining the Forces for Disas-sembly of Modular Acetabular DevicesF1877 Practice for Characterization of ParticlesF2033 Specification fo
12、r Total Hip Joint Prosthesis and HipEndoprosthesis Bearing Surfaces Made of Metallic,Ceramic, and Polymeric Materials2.2 ISO Standards:4ISO 5832-4 Implants for SurgeryMetallic MaterialsPart4: Cobalt-Chromium-Molybdenum Casting AlloyISO 5832-12 Implants for SurgeryMetallic MaterialsPart 12: Wrought C
13、obalt-Chromium-Molybdenum AlloyISO 7206-2 Implants for SurgeryPartial and Total HipJoint ProsthesesPart 2: Articulating Surfaces Made of1This guide is under the jurisdiction of ASTM Committee F04 on Medical andSurgical Materials and Devices and is the direct responsibility of SubcommitteeF04.22 on A
14、rthroplasty.Current edition approved March 15, 2015. Published May 2015. DOI: 10.1520/F3047M-15.2The boldface numbers in parentheses refer to the list of references at the end ofthis standard.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at ser
15、viceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.4Available 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 Har
16、bor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1Metallic, Ceramic and Plastics MaterialsISO 14242-1 Implants for SurgeryWear of Total Hip-JointProstheses. Part 1: Loading and Displacement Parametersfor Wear-Testing Machines and Corresponding Environ-mental Conditions for Test
17、ISO 14242-2 Implants for SurgeryWear of Total Hip-JointProstheses. Part 2: Methods of MeasurementISO 14242-3:2009 Implants for SurgeryWear of TotalHip-Joint ProsthesesPart 3: Loading and DisplacementParameters for Orbital Bearing Type Wear TestingISO 17853 Wear of Implant MaterialsPolymer and MetalW
18、ear ParticlesIsolation, Characterization and Quantifi-cation3. Terminology3.1 Definitions:3.1.1 acetabular linerportion of the modular acetabulardevice with an internal hemispherical socket intended toarticulate with the head of a femoral prosthesis. The externalgeometry of this component interfaces
19、 with the acetabular shellthrough a locking mechanism which may be integral to thedesign of the liner and shell or may rely upon additionalcomponents (for example, metal ring, screws, and so forth).3.1.2 acetabular shellthe metallic external, hollow struc-ture that provides additional mechanical sup
20、port or reinforce-ment for an acetabular liner and whose external featuresinterface directly with the bones of the pelvic socket (forexample, through bone cement, intimate press-fit, coatings forattachment to bone cement or tissue, integral screw threads,anchoring screws, pegs, and so forth). The ac
21、etabular shell maybe solid or contain holes for fixation to the pelvis or attachmentof instrumentation.3.1.3 acetabular liner/shell anglethe angle between thepolar axis of the acetabular articulating surface and thehorizontal (see ISO 14242 Part 1 paragraph 7.4).3.1.4 alloy fabricated formthe raw ma
22、terial form of themetallic alloy and any processing techniques used to fabricatethe final form of the implant.3.1.5 breakaway weara higherunexpected wear rate thatfollows a period of steady-state wear as illustrated in Fig. 2.3.1.6 breakaway wear with recoverya breakaway wearrate that returns to the
23、 lower steady state wear rates. Thebreakaway/recovery phenomenon can be a single event or asmultiple episodic events during the otherwise steady-stateconditions as illustrated in Fig. 2.3.1.7 ceramic-on-ceramic hip prosthesisa device intendedto replace a human hip joint in which the ball and cuparti
24、culating surfaces are composed of high purity alumina oralumina matrix composite ceramics. The ball is attached to anintramedullary femoral stem. Device articulating componentsmanufactured from other ceramic materials or with coated orelementally modified surfaces may have special concernswhich are
25、not addressed in the scope of this guide.3.1.8 contact patch edge to rim (CPER) distancefor agiven acetabular liner orientation the arc distance between theedge of a calculated Hertzian contact area caused bya3kNjoint reaction force and the last portion of articulating surfaceon the acetabular liner
26、 as illustrated in Fig. 1.3.1.9 coordinate measuring machine (CMM)an auto-mated system that is capable of making and recording mea-surements in three dimensions with high precision in a con-trolled volume of space.FIG. 1 Illustration of Cup Articular Arc AngleF3047M 1523.1.10 cup articular arc angle
27、the angle subtended by thearticular surface of the acetabular component. It can bedetermined with a computer aided design system or manualmeasurements. With the head placed in the acetabular liner, itis the minimum angle in a plane bisecting the head and theliner, formed by the last contact points b
28、etween the bearingsurfaces and the rotational center of the head. It will be 180 orless. It is illustrated in Fig. 2.3.1.11 dwell durationthe length of time that a wear test ispaused in a test mode in order to evaluate the effect ofperiodically stopping and starting the hip simulator articula-tion.3
29、.1.12 head to cup radial clearancethe radius of the cupbearing articular surface minus the radius of the head articularsurface.3.1.13 lubricant filma fluid film trapped between thearticulating surfaces of a hip joint that helps limit direct contactbetween the articulating surfaces.3.1.14 metal-on-me
30、tal hip prosthesisa device intended toreplace a human hip joint in which the ball and liner articulat-ing surfaces are often composed of high carbon version ofCo28Cr6Mo cobalt alloy. The ball may be attached to anintramedullary stem or a surface cover for the femoral head.3.1.15 runaway wearan initi
31、al high wear rate, that showsno sign of achieving a lower steady-state wear rate as illus-trated in Fig. 2.3.1.16 run-in wearwear that occurs when the componentsare first implanted in-vivo, or during the initial phase of anin-vitro hip simulator test as illustrated in Fig. 2. During thisperiod, wear
32、 rates are typically higher than during steady-stateas the head and cup wear into conformity with each other andany initially contacting surface asperities or form errors areworn away. In hip simulator wear tests, the run in phase is oftenconsidered to be about 1 million cycles. The transition toste
33、ady-state wear can be estimated graphically from the plot oftotal wear vs. number of cycles.3.1.17 serum protein contentthe concentration of proteinmolecules present in serum, usually expressed in grams perliter. The value is usually supplied by the commercial sourcefor the serum.3.1.18 steady-state
34、 wearwear rates that occur after atransient run-in wear period as illustrated in Fig. 2. Typically,the steady-state wear rate is less than the run-in wear rate. Inhip simulator wear tests the steady state rate typically isreached after 1 million cycles and above.3.1.19 third body wearthe increased w
35、ear that occurs dueto particle(s) not permanently attached to the articulatingsurfaces being present in the articulation. The source ofparticle(s) can be external to the articulating surfaces orcoming from the articulating surfaces.3.1.20 volumetric wear ratethe rate of material volumelost from both
36、 articulating surfaces.FIG. 2 Different Modes/Phases of Wear Illustrated SchematicallyF3047M 1534. Summary of Practice4.1 A conventional hip simulator wear test should be per-formed according to ISO 14242 Part 1 or Part 3 for five millioncycles. This will be used as a basis for comparison of theresu
37、lts of any high demand test regime.Any high demand weartest regime should use the ISO 14242 Part 1 or Part 3 standardas the starting point and high demand parameters should bemade as modifications to that standard. The ISO 14242 Part 3standard may not be suitable for high demand wear tests thatrequi
38、re modification of the articulating motion, because themotion cycle is built into the test machine hardware and cantbe modified.4.2 The high demand wear test can be performed as acontinuation of the conventional ISO 14242 Part 1 test or runas a separate test. High demand test features will be added
39、tothe high demand wear test and justified as clinically relevant.This will require an understanding of the potential interactionsof the possible high demand modes which would indicate aseries of shorter duration tests. A final high demand test(s) forthe preclinical evaluation of a device shall inclu
40、de a testprotocol of at least 5 million cycles. These high demand weartest cycles will be in addition to the conventional 5 millioncycles of wear testing.5. Significance and Use5.1 The current hip simulator wear test standards (ISO14242 Part 1 or Part 3) stipulate only one load wave form andone set
41、of articulation motions. There is a need for moreversatile and rigorous wear test regimes, but the knowledge ofwhat represents realistic high demand wear test features islimited. More research is clearly needed before a standard canbe written that defines what a representative high demand weartest s
42、hould include. The objective of this guide is to adviseresearchers on the possible high demand wear test features thatshould be included in evaluation of hard-on-hard articulations.5.2 This guide makes suggestions of what high demand testfeatures may need to be added to an overall high demand wearte
43、st regime. The features described here are not meant to be allinclusive. Based on current knowledge they appear to berelevant to adverse conditions that can occur in clinical use.5.3 All the test features, both conventional and high demandcould have interactive effects on the wear of the components.
44、6. Test Samples6.1 The materials and articulating geometry of the hard-on-hard system should be representative of the system intended forclinical use. The acetabular components must have the samegeometry as the acetabular system intended for clinical usebecause the stiffness of the acetabular system
45、 could affect theresponse to loads and motions at the articulating surface.6.2 The test parts should receive all of the processing that isintended for product intended for clinical use including steril-ization. There is no literature reporting any detrimental effectsof gamma sterilization or any oth
46、er sterilization methods usedfor orthopedic devices on the physical or chemical propertiesof metallic alloys. However, it may be advisable to sterilizeeverything prior to definitive tests for preclinical evaluation tomake all parts as close to clinical product as possible. Coatingson non-articulatin
47、g surfaces of the test parts could createproblems with the handling of the parts and weight lossmeasurements during testing. It may be necessary to have testparts without the non-articulating surface coatings. However,any thermal processing the test parts would receive as part ofany coating process
48、should still be performed. Particulatebased coating could be a source for third body wear particles,but random particle loss interferes with the repeatability of thetest. Consideration should also be given to using particulatefrom the coatings as controlled third body particle sources.6.3 No precond
49、itioning is required for the test samples otherthan careful handling to assure that they remain clean and freeof contamination prior to start of testing.6.4 The diameter and acetabular sizing must be justified asworst case for the wear tests. There are many possible factorsthat could make a hard-on-hard couple a “Worst Case”. Thediameter of the articulation, head to cup radial clearance, thethickness of material in the liner and the shell, the design ofmodularity of the liner and the shell, or the sphericity of thearticulations could all potent
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