ASTM_F_732_-_00_2011.pdf

Designation:F73200(Reapproved 2011)Standard Test Method forWear Testing of Polymeric Materials Used in Total JointProstheses1This standard is issued under the fixed designation F732;the number immediately following the designation indicates the year of originaladoption or,in the case of revision,the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscriptepsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method describes a laboratory method forevaluating the wear properties of combinations of materialsthat are being considered for use as bearing surfaces of humantotal joint prostheses.The body of this test method containsgeneral methods which apply to all types of prosthesis wearapplications while individual annexes describe specific weartest methods and clinical validation criteria tailored to eachdistinct wear application(for example,linear reciprocatingmotion,ball-cup(“hip-type”)wear,delamination wear,etc.).Itis the intent of this test method to rank materials,within eachwear application,for polymer wear rates under simulatedphysiological conditions.It must be recognized,however,thatcontact geometries and wear motions are simplified using suchmethods.This test method,therefore,represents only an initialstage in the full wear characterization of a candidate material.1.2 All candidate materials should be tested in an appropri-ate joint simulator apparatus using prototype prostheses beforebeing used in clinical trials in patients.The tests described inthis test method are used to quickly and reliably screen materialcombinations for wear performance in different orthopaedicwear applications prior to committing them to more expensiveand time-consuming joint simulator testing.In addition,thesesimplified tests can be used to relate material,surface finish,orother parameters to wear behavior on a more practical basisthan is possible in joint simulator tests.1.3 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard.The values stated ineach system may not be exact equivalents;therefore,eachsystem shall be used independently of the other.Combiningvalues from the two systems may result in non-conformancewith the standard.2.Referenced Documents2.1 ASTM Standards:2D883 Terminology Relating to PlasticsF75 Specification for Cobalt-28 Chromium-6 MolybdenumAlloy Castings and Casting Alloy for Surgical Implants(UNS R30075)F86 Practice for Surface Preparation and Marking of Metal-lic Surgical ImplantsF648 Specification for Ultra-High-Molecular-Weight Poly-ethylene Powder and Fabricated Form for Surgical Im-plantsF799 Specification for Cobalt-28Chromium-6MolybdenumAlloy Forgings for Surgical Implants(UNS R31537,R31538,R31539)F1537 Specification for Wrought Cobalt-28Chromium-6Molybdenum Alloys for Surgical Implants(UNSR31537,UNS R31538,and UNS R31539)F2025 Practice for Gravimetric Measurement of PolymericComponents for Wear AssessmentG40 Terminology Relating to Wear and Erosion3.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 wearfor the purpose of this test method,the progres-sive loss of material from the polymer specimen as a result ofthe oscillating motion against the counterface under load.Wearmay be generated by several mechanisms including adhesion,two or three body abrasion,surface fatigue,or other processes.3.1.2 wear ratethe volume of material lost due to wear perunit of sliding distance(or per million wear cycles if complexmotion patterns result in a non-uniform sliding distance acrossthe specimen;see 4.3).1This test method is under the jurisdiction ofASTM Committee F04 on Medicaland Surgical Materials and Devices and is the direct responsibility of SubcommitteeF04.15 on Material Test Methods.Current edition approved June 1,2011.Published July 2011.Originally approvedin 1982.Last previous edition approved in 2006 as F732 00(2006).DOI:10.1520/F0732-00R11.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 4.Significance and Use4.1 This test method is intended to be performed in con-junction with pin-on-flat wear machines or similar machinesthat are designed to evaluate simplified specimen geometries.4.2 This test method is designed to evaluate combinations ofmaterials with respect to the amount of polymer wear,wherequantifiable wear occurs primarily on the polymeric compo-nent.With some combinations of materials,significant wear ofthe counterface may occur,with subsequent embedding ofcounterface debris particles in the polymer.Such an occurrencewill render the weight loss of the polymer specimen unreliableas an indicator of the polymer wear.4.3 Wear is reported as volume loss of the