ASTM F3210-22e1

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
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Designation: F3210 −22
Standard Test Method for
Fatigue Testing of Total Knee Femoral Components Under
Closing Conditions
This standard is issued under the fixed designation F3210; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
ε NOTE—The designation was updated editorially in March 2022.
1. Scope ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
1.1 This standard applies to metallic total knee femoral
mendations issued by the World Trade Organization Technical
components used in total knee arthroplasty (TKA). Femoral
Barriers to Trade (TBT) Committee.
components made of nonmetallic materials (for example,
ceramic, polymer) could possibly be evaluated using this test
2. Referenced Documents
method. However, such materials may include risks of new
failure mechanisms which are not considered in this test 2.1 ASTM Standards:
method. E4 Practices for Force Calibration and Verification of Test-
ing Machines
1.2 The procedure described in this standard is performed
E467 Practice for Verification of Constant Amplitude Dy-
ontotalkneefemoralcomponentsforsupportingdetermination
namic Forces in an Axial Fatigue Testing System
of fatigue behavior under closing-style loading conditions.
E468 Practice for Presentation of Constant Amplitude Fa-
Closing-style loading refers to forces that act to reduce the
tigue Test Results for Metallic Materials
femoral intercondylar depth, resulting in a tensile stress on the
E739 PracticeforStatisticalAnalysisofLinearorLinearized
articular surface of the femoral condyle. (See 3.2.2.)
Stress-Life (S-N) and Strain-Life (ε-N) Fatigue Data
1.3 Differentdesignscanbecharacterizedas,butnotlimited
E1823 TerminologyRelatingtoFatigueandFractureTesting
to, posterior cruciate ligament retaining (CR), posterior stabi-
F1800 Practice for Cyclic Fatigue Testing of Metal Tibial
lizing (PS), and revision.
Tray Components of Total Knee Joint Replacements
F2083 Specification for Knee Replacement Prosthesis
1.4 This standard does not address evaluation of femoral
components under opening-style loading conditions which F3140 Test Method for Cyclic Fatigue Testing of Metal
Tibial Tray Components of Unicondylar Knee Joint Re-
have also generated clinical failures. Under opening-style
loading conditions, forces are applied to the inner contour of placements
F3161 Test Method for Finite Element Analysis (FEA) of
the femoral component in a way that the forces act to increase
the intercondylar depth, or open the femoral component. Metallic Orthopaedic Total Knee Femoral Components
under Closing Conditions
1.5 Units—The values stated in SI units are to be regarded
2.2 ISO Standards:
as standard. No other units of measurement are included in this
ISO 5833 Implants for Surgery—Acrylic Resin Cements
standard.
ISO 7207-1 Implants for Surgery—Components for Partial
1.6 This standard does not purport to address all of the
and Total Knee Joint Prostheses—Part 1: Classification,
safety concerns, if any, associated with its use. It is the
Definitions and Designation of Dimensions
responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter-
3. Terminology
mine the applicability of regulatory limitations prior to use.
1.7 This international standard was developed in accor- 3.1 Definitions:
dance with internationally recognized principles on standard-
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
This test method is under the jurisdiction ofASTM Committee F04 on Medical contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
and Surgical Materials and Devices and is the direct responsibility of Subcommittee Standards volume information, refer to the standard’s Document Summary page on
F04.22 on Arthroplasty. the ASTM website.
Current edition approved March 15, 2022. Published March 2022. DOI: Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
10.1520/F3210-22E01. 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 States
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F3210 − 22
3.1.1 femoral intercondylar depth—distance between the 4. Summary of Test Method
anterior and posterior internal surfaces of the femoral
4.1 This method provides guidance on how to test a total
component, as defined in ISO 7207-1 and shown in Fig. 1(a).
knee femoral component in closing fatigue.Total knee femoral
3.1.2 total knee femoral component—a component of a total componentswillbetestedtosimulatesinglecondyleloadingat
knee joint prosthesis intended to be secured to the femur to 90° of tibiofemoral flexion.The highest load for which a group
replace its articulating surfaces. of samples completes the predefined runout without failure is
the maximum runout load. (See X1.1 for recommendations on
3.2 Definitions of Terms Specific to This Standard:
runout and X1.2 and X1.3 on methods to determine fatigue
3.2.1 bisection plane—for a femoral component that does
strength.)
not have posterior curvature in the transverse plane (that is, flat
in the transverse view), the condyle bisection plane is a plane
5. Significance and Use
parallel to the sagittal plane that bisects the medial or lateral
5.1 Clinical fractures of total knee femoral components
posterior condyle at 90° of tibiofemoral flexion (shown in Fig.
have been observed and reported in the literature (1-12). (See
1(b), medial condyle).
X1.4.)
3.2.2 femoral closing—the result of a force that acts to
5.2 This test method provides a procedure to perform
reduce the femoral intercondylar depth, resulting in a tensile
fatigue testing on total knee femoral components under closing
stress on the articular surface of the femoral condyle.
conditions caused by an unsupported condyle that result in a
3.2.3 potting medium—a casting or embedding medium for
tensile stress on the articular surface and a compressive stress
supporting the specimen and providing fixation to the test
on the interior, beveled surfaces.
frame.
5.3 This test method is intended to evaluate the fatigue
3.2.4 runout—predetermined number of cycles at which the
performance of knee femoral components under a simulated
testing on a particular specimen will be stopped, and no further
articulation loading condition. The load acts to move the
testing on that specimen will be performed.
posterior femoral condyle toward the anterior flange.
3.2.5 transverse condylar crown—for a femoral component
that has a posterior curvature in the transverse plane, the peak
of this curvature is the transverse condylar crown (shown in 4
The boldface numbers in parentheses refer to a list of references at the end of
Fig. 1(b), lateral condyle). this standard.
FIG. 1 Terminology and Test Configuration
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F3210 − 22
5.4 This test method simulates a clinically severe condition 6.5.3 The minimum spacer thickness is recommended to be
in which all bony support is lost and one condyle is supporting at least 6 mm to minimize the chance of spacer fracture under
the complete load at the knee joint at 90° of tibiofemoral load.
flexion. 6.5.4 The recommended spacer diameter is at least 13 mm.
5.5 Testing in accordance with this test method typically
7. Hazards
produces regions of high tensile stress in the intercondylar
7.1 Hazards may include, but are not limited to, the follow-
notch and on the articular surface where the anterior flange
ing:
transitions to condyle.
7.1.1 Physical Hazards—Mechanical testing may expose
5.6 Theloadingoftotalkneefemoralcomponentsusingthis
the user to several hazards including crush hazards, pinch
test method may differ from actual in vivo loading conditions.
points,andsharpobjects.Usersshouldbeawareofhazardsand
The results obtained here cannot be used to directly predict in
utilize appropriate safety precautions.
vivo performance. However, this test method is designed to
7.1.2 Chemical Hazards—The use of potting media, such as
enable comparison between the fatigue performance of differ-
poly(methyl methacrylate) (PMMA) bone cement and epoxy,
ent total knee femoral component designs when tested under
are potentially hazardous and may cause irritation to the skin,
similar closing conditions.
eyes, and nasal passages. The mixing of the potting medium
and the potting of the femoral component should be performed
6. Apparatus
in a fume hood or similarly well-ventilated area.
6.1 Perform the tests using a properly calibrated fatigue test
machine with adequate load capacity (see Practice E4 for
8. Sampling
guidance).
8.1 The test specimens shall conform to the final design
6.2 Analyze the dynamics of the machine to ensure that the
specifications. Specific processes in the manufacturing flow
desired periodic force amplitude is maintained for the duration
chart may be omitted if they have been proven to not affect the
of the test (see Practices E467 and E468 for guidance).
fatigue characteristics of the materials or devices. Design
characteristics include, but are not limited to, the following:
6.3 Thefatiguetestmachineshallhavealoadanddeflection
8.1.1 Material and post-manufacture treatment;
monitoring system such as the transducer mounted in line with
8.1.2 Dimensions and tolerances;
the specimen. Monitor the test loads and deflections continu-
8.1.3 Surface characteristics including surface roughness,
ously in the early stages of the test and periodically thereafter
surface features, and coatings; and
to ensure that the desired load cycle is maintained. The control
8.1.4 Sterilization method.
system shall maintain the varying load at all times to within
62 % of the magnitude of the largest compressive force being
9. Procedure
used.
9.1 Test the worst-case condyle and component size, and
6.3.1 The potting medium for the specimen(s) shall:
6.3.1.1 Not break under the load applied during testing; this shall be justified. Depending on the design, either the
medial or the lateral condyle may be the worst-case, and one
6.3.1.2 Not exhibit excessive deformation or creep; and
6.3.1.3 Bereproducibleinstrengthandothercharacteristics. method that can be used for this determination is Test Method
F3161.
(See X1.5 for recommended potting media.)
6.4 The load applicator shall be free to move in the 9.2 Test Specimen Preparation and Potting—Pot or fix the
transverse direction of load application. femoral component in such a manner that the load applied by
the fatigue test machine simulates a force acting at 90° 6 2° of
6.5 Damage to the femoral component can occur; therefore,
tibiofemoral flexion and 0° 6 2° of internal/external rotation
the use of a polymeric spacer and/or a lubricant between the
(Fig. 1). The depth of the femoral component into the potting
load applicator and the femoral component should be consid-
medium shall be sufficient such that the femoral component is
ered.
rigidly fixed and does not loosen during testing, while leaving
6.5.1 The spacer should possess sufficient stiffness and
the regions of highest stress exposed. The potting level should
creep resistance. Recommended spacer materials are ultra high
be at least 5 mm below the intercondylar notch to expose this
molecular weight polyethylene (UHMWPE) or acetal co-
area, since this is typically a region of concentrated stress.
polymer.
Additional external fixation (such as a plate and a clamp) that
6.5.2 In order to maintain the load application centered on
does not interfere with the test may be used over the potting
the condyle, the side of the spacer/load applicator should
medium to increase the fixation strength.
feature a slight concavity with a large radius relative to the
curvature of the femoral condyle. This provides self-centering 9.3 Alignment—The condyle to be tested shall be aligned to
of the applicator on the condyle while still approximating point the fatigue machine load axis. The load applicator shall be free
contact. If a flat spacer/load applicator is used, the user must to move in the transverse direction of load application. One
ensure that the load applicator does not migrate off of the method of aligning during setup is provided in X1.6.
femoralcomponentduringtesting.Ifadhesiveisusedtosecure 9.3.1 Sagittal View Alignment—In the sagittal view, position
theloadapplicatortothefemoralcomponent,evidencemustbe the condyle under the load axis of the fatigue test machine to
provided that the adhesive does not shield the femoral compo- make contact with the posterior condyle at its peak curvature
nent from stress. with a tolerance of 61 mm.
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F3210 − 22
9.3.2 Transverse View Alignment: 10.2 The test report should include the following:
9.3.2.1 If the posterior articulation surface is flat in the
10.2.1 Test setup parameters:
transverse view, position the load application axis 61mm
10.2.1.1 Fixation method and potting
...