ASTM F2580-2018 Standard Practice for Evaluation of Modular Connection of Proximally Fixed Femoral Hip Prosthesis.pdf

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1、Designation: F2580 18Standard Practice forEvaluation of Modular Connection of Proximally FixedFemoral Hip Prosthesis1This standard is issued under the fixed designation F2580; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the yea

2、r 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 practice covers a procedure for the fatigue testingof metallic femoral hip prostheses used in hip joint repl

3、ace-ments. This practice covers the procedures for the performanceof fatigue tests on metallic femoral hip stems using a cyclic,constant-amplitude force. It applies to hip prostheses thatutilize proximal metaphyseal fixation and are of a modularconstruct, and it is intended to evaluate the fatigue p

4、erformanceof the modular connections in the metaphyseal filling (that is,proximal body) region of the stem.1.2 This practice is intended to provide useful, consistent,and reproducible information about the fatigue performance ofmetallic hip prostheses while held in a proximally fixatedmanner, with t

5、he distal end not held by a potting medium.1.3 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of

6、the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.1.5 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decis

7、ion on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2E467 Practice for Verification of Constant Amplitude Dy-namic Forces in an Axial F

8、atigue Testing SystemE468 Practice for Presentation of Constant Amplitude Fa-tigue Test Results for Metallic MaterialsE1823 Terminology Relating to Fatigue and Fracture Testing2.2 ISO Standards:3ISO 72064 Implants for surgery - Partial and total hip jointprostheses - Part 4: Determination of enduran

9、ce proper-ties and performance of stemmed femoral components3. Terminology3.1 Definitions:3.1.1 R value, nThe R value is the ratio of the minimumload to the maximum load.R 5minimum loadmaximum load3.2 Definitions of Terms Specific to This Standard:3.2.1 extraction, nremoval of the femoral hip implan

10、tfrom the femur during surgery.3.2.2 extractor hole, na hole in the proximal body of thestem in which an apparatus is placed to remove the implantfrom the femur.3.2.3 femoral head, nconvex spherical bearing memberfor articulation with the natural acetabulum or prostheticacetabulum.3.2.4 femoral head

11、 offset, nthe perpendicular distancefrom the centerline of the implant stem to the center of thefemoral head.3.2.5 frontal plane, nthe plane that lies in the medial-lateral direction of the implant. Adduction occurs in this plane.3.2.6 implant centerline, nthe axis that runs verticallyfrom the proxi

12、mal body of the implant down the center of thestem to the distal end.3.2.7 pivot axis, nthe center of rotation of the pivot fixture(and prosthesis potted within it) within the test fixture setup; itslocation is determined by the intersection of the neck and stemcenterlines of the prothesis (Figs. 1

13、and 2).1This practice is under the jurisdiction ofASTM Committee F04 on Medical andSurgical Materials and Devices and is the direct responsibility of SubcommitteeF04.22 on Arthroplasty.Current edition approved July 1, 2018. Published September 2018. Originallyapproved in 2007. Last previous edition

14、approved in 2013 as F2580 13. DOI:10.1520/F2580-18.2For 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

15、 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 StatesThis international standard was developed in accordance with internati

16、onally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1FIG. 1 Free Body Diagram of Test SetupFIG. 2 Schemat

17、ic Representation of Test SetupF2580 1823.2.8 pivot fixture, nthe fixture in which the specimen ispotted, and is attached to the main test fixture; characterized bytwo pins on the side that serve as the pivot axis.3.2.9 rotational plane, nthe plane that lies perpendicularto the stem axis of the impl

18、ant.3.2.10 sagittal plane, nthe plane that lies perpendicular tothe frontal plane; flexion occurs in this plane.4. Significance and Use4.1 This practice can be used to describe the effects ofmaterials, manufacturing, and design variables on the fatigueperformance of metallic femoral hip prostheses s

19、ubject tocyclic loading for large numbers of cycles.4.2 The loading of femoral hip designs in vivo will, ingeneral, differ from the loading defined in this practice. Theresults obtained here cannot be used to directly predict in vivoperformance. However, this practice is designed to allow forcompari

20、sons between the fatigue performance of differentmetallic femoral hip designs when tested under similar condi-tions.4.3 In order for fatigue data on femoral hip prostheses to becomparable, reproducible, and capable of being correlatedamong laboratories, it is essential that uniform procedures beesta

21、blished.5. Specimen Selection5.1 The test component selected shall have the same geom-etry as the final product, and shall be in finished condition. Thetest component shall be of the worst-case size and configura-tion (that is, the component that produces the highest stresses)of the implant family t

22、o be tested.5.2 The femoral head component selected for load applica-tion shall be of the same design and material as a currentproduct in use, but may be previously tested.5.3 The femoral head selected shall offer the greatest loadoffset from the hip centerline, to represent a worst-casebending scen

23、ario during testing.6. Apparatus6.1 The hip implant may be tested in different orientationsto better reproduce specific testing conditions that are beingevaluated. For example: An anatomical orientation of 9flexion, and 10 adduction (per ISO 7206-4), or vertically inboth planes. The criteria used to

24、 determine the orientationshould be reported.6.2 Care shall be taken to ensure that the fixation of theimplant does not produce abnormal stress concentrations thatcould change the failure mode of the part.6.3 A fixed-bearing load applicator shall be used to keep thespecimen aligned in the chosen ori

25、entation during testing, aswell as a fixture that allows the stem to bend during testing,such as a u-joint.6.4 The fixture used to hold the implant during testingshould have a reaction bolt that will oppose the loading on thefemoral head, keeping the implant in equilibrium. The positionof the reacti

26、on bolt should be adjustable to accommodate stemsof different lengths and design features.6.5 The fixtures and aligning materials used should be of adesign that positions the implant, when potted, so that: thepoint defined by the intersection of the neck and stem center-lines is coincident with the

27、pivot axis (Fig. 1), the stem is fixedvertically in both medial/lateral and anterior/posteriordirections, the stem is aligned facing forward in the rotationalplane (that is, the frontal plane is normal to the pivot axis of thefixture (Fig. 3), and that any mating surfaces between modularcomponents o

28、f the specimen do not come in contact with thepotting medium.7. Equipment Characteristics7.1 Perform the tests on a fatigue test machine with ad-equate load capacity.7.2 Analyze the action of the machine to ensure that thedesired form and periodic force amplitude is maintained for theduration of the

29、 test (see Practice E467 or use a validatedstrain-gauged part).7.3 The test machine shall have a load monitoring systemsuch as a transducer mounted in line with the specimen.Monitor the test loads continuously in the early stages of thetest and periodically thereafter to ensure the desired load cycl

30、eis maintained. Maintain the varying load as determined bysuitable dynamic verification at all times to within 62 % of thelargest compressive force being used.8. Procedure8.1 This procedure details a potting method centered aboutpotting the proximal body portion of the implant first, andassembling t

31、he remainder of the implant after potting. Othermethods of potting the specimen exist, including methods forimplants that are not of a modular design, and may be used inplace of this, providing that the general terms and limitationsNOTE 1Once assembled, the pivot axis will be coincident with thepoin

32、t on the implant defined by the intersection of the neck and stemcenterlines.FIG. 3 Proximal Sleeve Component Potted in Pivot FixtureF2580 183are still achieved. The potting procedure used should beincluded in the test report.8.2 Specimen Preparation:8.2.1 Apply a moderate coat of lubricant (that is

33、, anyhousehold cooking spray) to the interior of the pivot fixture andany other fixture surfaces that will contact the potting mediumto prevent adhesion during potting.8.2.2 Align the proximal body component of the implant inthe pivot fixture, using the aligning materials to ensure it is inthe corre

34、ct orientation. Be sure the component and fixtures arefitted tightly so the specimen does not move during potting andcuring. The distal potting level shall be at the distal surface ofthe proximal body component (see Figs. 1 and 2).8.2.3 An appropriate potting medium should be chosenwhich displays th

35、e correct load carrying capabilities andresistance to cracking or crumbling during fatigue. Examplesof different potting media include bone cement, dental acrylic,or a low melting point alloy. The type and manufacturer of thepotting material chosen should be reported.8.2.4 Pour the potting material

36、into the pivot fixture, aroundthe specimen. If necessary, use another material such as tape orclay to block any gaps to prevent the material from seepingthrough to any area outside the pivot fixture. Care should betaken to ensure that potting medium does not come in contactwith any mating surfaces o

37、n the proximal component.8.2.5 The proximal potting level shall be at the proximalsurface of the proximal body component (see Figs. 1 and 2).No potting material should enter any space between modularcomponents of the specimen.8.2.6 Allow the material to cure completely before continu-ing.8.3 Specime

38、n Assembly and Impaction:8.3.1 Remove all secondary fixtures used to align theimplant in the pivot fixture.8.3.2 Clean the internal and distal surfaces of the proximalcomponent with acetone to remove any potting or othermaterial that came into contact with the surface. Avoid allow-ing the acetone to

39、 contact the good potting material.8.3.3 Assemble the remainder of the implant, ensuring thatthe stem remains aligned properly in all planes of interest.8.3.4 Assemble the modular components of the stem bodyas specified by the surgical technique for the device.8.3.5 Place the femoral head on the nec

40、k taper of the hipimplant and impact the head on the taper with three blows witha rubber mallet.8.3.6 Determine the femoral head offset from the centerlineof the stem. This can be done by means of a height gauge oroptical comparator.8.4 Test Setup:8.4.1 Attach the pivot fixture with the specimen to

41、the testframe fixture in the correct orientation.8.4.2 Attach the polyethylene load applicator to the actuator.8.4.3 Bring the load applicator into contact with the femoralhead of the specimen so that a low load (approximately 10 lbf)is applied.8.4.4 Vertically position the reaction bolt assembly so

42、 that itis located 66 mm from the pivot axis (Fig. 2). If the stem designincludes a coronal slot, the reaction bolt should be locatedabove the highest level of the coronal slot.NOTE 1The vertical position of the reaction bolt may be modified toaccommodate designs and test purposes different from wha

43、t is explainedin this practice.8.4.5 Adjust the main fixture and the pivot fixture so that thespecimen is aligned at the proper angles in the frontal plane(adduction) and in the sagittal plane (flexion) (See 6.1). Thetest setup is represented in Fig. 2.8.4.6 Proper measures should be taken to ensure

44、 that thefixturing is secure and the specimen or equipment does not getdamaged should unloading occur during testing8.4.7 Test FrequencyRun all tests at a frequency of 10 Hzor less. constant frequency with a maximum allowable fre-quency of 10 Hz. Take care to ensure that the test machine canmaintain

45、 the applied load at the chosen frequency and thatresonant conditions are not reached.8.4.8 Input Loading ProfileRun all tests using a sinusoidalwaveform input load with an R value of 10.0.NOTE 2In strict terms, since the force applied to the femoral head iscompressive, the maximum force is the smal

46、lest negative amplitude.Consequently, the R value is ten when the negative signs cancel eachother. In terms of applied bending moment at the potting plane, the Rvalue would be 0.1. See Terminology E1823 for the definition of the Rvalue.9. Test Termination9.1 Continue the test until the femoral prost

47、hesis fails oruntil a predetermined number of cycles have been applied tothe implant. The suggested number of cycles is ten million.Failure may be defined as: a fracture of the femoral implant;formation of a crack detectable by eye, fluorescent dyepenetrant, or other non-destructive means; or exceed

48、ing apredetermined deflection limit.10. Report10.1 Report the fatigue test specimens, procedures, andresults in accordance with Practice E468.10.2 In addition, report the following parameters:10.2.1 Femoral implant (size, configuration, material, andso forth),10.2.2 Femoral head size and offset,10.2

49、.3 Femoral head offset measured from stem center,10.2.4 Method of assembly of the modular components,10.2.5 Stem orientation and the criteria used to determine it(per 6.1),10.2.6 Distance to reaction bolt from distal potting plane,10.2.7 Potting procedure,10.2.8 Potting medium,10.2.9 Largest compressive load,10.2.10 R value,10.2.11 Cycles to failure,10.2.12 Mode and location of failures,10.2.13 Test environment, and10.2.14 Test frequency.11. Precision and Bias11.1 A precision and bias statement does not exist for thispractice.F2580 18412. Keywords12.1 arth