ASTM F1440-92(2008)

Standard Practice for Cyclic Fatigue Testing of Metallic Stemmed Hip Arthroplasty Femoral Components Without Torsion (Withdrawn 2012)

SIGNIFICANCE AND USE
This practice can be used to describe the effects of materials, manufacturing, and design variables on the fatigue resistance of metallic stemmed femoral components subjected to cyclic loading for relatively large numbers of cycles. The recommended test assumes a “worst case” situation where proximal support for the stem has been lost. It is also recognized that for some materials the environment may have an effect on the response to cyclic loading. The test environment used and the rationale for the choice of that environment should be described in the report.
It is recognized that actual in vivo loading conditions are not ofconstant amplitude. However, there is not sufficient information available to create standard load spectrums for metallic stemmed femoral components. Accordingly, a simple periodic constant amplitude force is recommended.
In order for fatigue data on femoral stems to be useful for comparison, it must be reproducible among different laboratories. Consequently, it is essential that uniform procedures be established.
SCOPE
1.1 This practice describes a method for the fatigue testing of metallic stemmed femoral components used in hip arthroplasty. The described method is intended to be used to evaluate the comparison of various designs and materials used for stemmed femoral components used in the arthroplasty. This practice covers procedures for the performance of fatigue tests using (as a forcing function) a periodic constant amplitude force.
1.2 This practice applies primarily to one-piece prostheses and modular components, with head in place such that prostheses should not have an anterior/posterior bow, and should have a nearly straight section on the distal 50 mm of the stem. This practice may require modifications to accommodate other femoral stem designs.
1.3 The values stated in SI units are to be regarded as the standard.
1.4 For additional information see Refs. (1-5) .
WITHDRAWN RATIONALE
This practice describes a method for the fatigue testing of metallic stemmed femoral components used in hip arthroplasty. The described method is intended to be used to evaluate the comparison of various designs and materials used for stemmed femoral components used in the arthroplasty. This practice covers procedures for the performance of fatigue tests using (as a forcing function) a periodic constant amplitude force.
Formerly under the jurisdiction of Committee F04 on Medical and Surgical Materials and Devices, this practice was withdrawn in December 2012 because a more updated ISO hip fatigue testing document exists.

General Information

• Status: Withdrawn
• Publication Date: 31-May-2008
• Withdrawal Date: 30-Nov-2012
• ICS: 11.040.40 - Implants for surgery, prosthetics and orthotics
• Technical Committee: F04 - Medical and Surgical Materials and Devices
• Drafting Committee: F04.22 - Arthroplasty

Relations

• Replaces: ASTM F1440-92(2002) - Standard Practice for Cyclic Fatigue Testing of Metallic Stemmed Hip Arthroplasty Femoral Components Without Torsion
• Effective Date: 01-Jun-2008
• Referred By: ASTM F1875-98(2022) - Standard Practice for Fretting Corrosion Testing of Modular Implant Interfaces: Hip Femoral Head-Bore and Cone Taper Interface
• Effective Date: 01-Jun-2008

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: F1440 − 92 (Reapproved2008)
Standard Practice for
Cyclic Fatigue Testing of Metallic Stemmed Hip Arthroplasty
Femoral Components Without Torsion
This standard is issued under the fixed designation F1440; 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.
1. Scope 3.1.1 cantilever plane—a plane perpendicular to the line of
load application at the level on the stem where the stem
1.1 This practice describes a method for the fatigue testing
becomes unsupported.
of metallic stemmed femoral components used in hip arthro-
3.1.2 distal stem axis—the centerline in the anterior/
plasty.The described method is intended to be used to evaluate
posterior projection of the most distal 50 mm of the stem.
the comparison of various designs and materials used for
3.1.3 estimated maximum bending moment—the maximum
stemmed femoral components used in the arthroplasty. This
load times the unloaded moment arm.
practice covers procedures for the performance of fatigue tests
3.1.4 geometric centroid (cantilever plane)—the point in a
using (as a forcing function) a periodic constant amplitude
cross-sectional area of the cantilever plane whose coordinates
force.
are the mean values of the coordinates of all the points in the
1.2 This practice applies primarily to one-piece prostheses
area.
and modular components, with head in place such that pros-
3.1.5 line of load application—the loading axis of the test
theses should not have an anterior/posterior bow, and should
machine.
have a nearly straight section on the distal 50 mm of the stem.
3.1.6 Reference Line L1, distal stem axis—themedial-lateral
This practice may require modifications to accommodate other
(M-L) centerline of the most distal 50 mm of stem in the A-P
femoral stem designs.
projection.
1.3 The values stated in SI units are to be regarded as the 3.1.7 Reference Line L2:
3.1.7.1 collared device—the plane of the distal side of the
standard.
collar in the A-P projection.
1.4 For additional information see Refs. (1-5).
3.1.7.2 collarless device—the resection plane recommended
for the device in the A-P projection.
2. Referenced Documents
3.1.8 Reference Point P1—the spherical center of the pros-
2.1 ASTM Standards:
thesis head.
E4 Practices for Force Verification of Testing Machines
3.1.9 Reference Point P3:
E466 Practice for Conducting Force Controlled Constant
3.1.9.1 collared device—the intersection of the principal
Amplitude Axial Fatigue Tests of Metallic Materials
axisofthecollar(L2)withthemedialsurfaceofthesteminthe
E467 Practice for Verification of Constant Amplitude Dy-
A-P projection.
namic Forces in an Axial Fatigue Testing System
3.1.9.2 collarless device—the intersection of the resection
E468 Practice for Presentation of Constant Amplitude Fa-
plane (L2) with the medial surface of the stem in the A-P
tigue Test Results for Metallic Materials
projection.
3.1.10 Reference Point P4—the distal tip of the stem.
3. Terminology 3
3.1.11 Reference Point P6 —the intersection of the cantile-
3.1 Definitions and Symbols (see Fig. 1 and Fig. 2):
ver plane with the medial surface of the stem in the A-P
projection.
3.1.12 R value—the ratio of the minimum force to the
ThispracticeisunderthejurisdictionofASTMCommitteeF04onMedicaland
maximum force.
Surgical Materials and Devices and is the direct responsibility of Subcommittee
minimum force
F04.22 on Arthroplasty.
R 5
CurrenteditionapprovedJune1,2008.PublishedJuly2008.Originallyapproved
maximum force
in 1992. Last previous edition approved in 2002 as F1440 – 92 (2002). DOI:
10.1520/F1440-92R08.
2 3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or The reference points and lines are consistent with the Proposed Standard
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Specification for Cementable Total Hip Prostheses with Femoral Stems. The
Standards volume information, refer to the standard’s Document Summary page on reference points “P2” and “P5” in that proposed specification are not relevant to this
the ASTM website. practice. Consequently, they are not used in this practice.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F1440 − 92 (2008)
3.1.16 unloaded moment arm—the perpendicular distance
between the line of load application and the geometric centroid
of the stem cross section at the cantilever plane.
3.1.17 unsupported stem length—the vertical distance be-
tween Point P3 and the cantilever plane.
3.2 See Figs. 1 and 2.
4. Significance and Use
4.1 This practice can be used to describe the effects of
materials, manufacturing, and design variables on the fatigue
resistance of metallic stemmed femoral components subjected
to cyclic loading for relatively large numbers of cycles. The
recommended test assumes a “worst case” situation where
proximal support for the stem has been lost. It is also
recognized that for some materials the environment may have
an effect on the response to cyclic loading. The test environ-
ment used and the rationale for the choice of that environment
should be described in the report.
4.2 Itisrecognizedthatactual in vivoloadingconditionsare
not ofconstant amplitude. However, there is not sufficient
information available to create standard load spectrums for
metallic stemmed femoral components. Accordingly, a simple
periodic constant amplitude force is recommended.
4.3 In order for fatigue data on femoral stems to be useful
FIG. 1 Collared Device
for comparison, it must be reproducible among different
laboratories. Consequently, it is essential that uniform proce-
dures be established.
5. Specimen Selection
5.1 The specimen selection should have the same geometry
as the final finished product, and the stem should be in the final
finished condition.
6. Apparatus
6.1 Thespecimenshallbeconstrainedbyasuitablegrouting
agent within a rigid cavity. A common grouting agent used is
poly methyl methacrylate (PMMA—bone cement) that is
polymerized in place. The minimum thickness of the grouting
agent should be 1 cm. Although bone cement is the recom-
mended grouting agent, other material may be used provided it
does not chemically or mechanically interact with the test
specimen.
6.2 The test fixtures shall be constructed so that the line of
load application is in the implant anterior/posterior symmetry
plane of the supported portion of the stem.
6.3 The test fixtures shall be constructed so that the line of
load application passes through the ball center.
FIG. 2 Collarless Device
6.4 A ball- or roller-bearing low-friction mechanism shall
be included in the loading apparatus to minimize loads not
perpendicular to the cantilever plane. An example of such a
mechanism is given in Appendix X1.
3.1.13 Stem Reference Angle X—the angle between the stem
reference line and the line of load application.
7. Equipment Characteristics
3.1.14 stem reference line—a line passing through Refer-
ence Point P6 and the center of the prosthesis head (P1). 7.1 The action of the machine should be analyzed to ensure
3.1.15 supported stem length—the vertical distance between that the desired form and periodic force amplitude is main-
the distal tip of the stem (P4) and the cantilever plane. tained for the duration of the test. (See Practice E467.)
F1440 − 92 (2008)
7.2 The test machine should have a load monitoring system A possible means would be to use a shadowgraph of the
such as the transducer mounted in line with the specimen. The anterior posterior projection as shown in Fig. 1.
test loads should be monitored continuously in the early stages
8.6 Estimate the amount of horizontal deflection of the head
of the test and periodically thereafter to ensure the desired load
in response to the periodic forcing function one time after the
cycle is maintained. The varying load as determined by
beginning of each test. Possible methods include dial gages,
suitable dynamic verification should be maintained at all times
optical micrometers, or linear scales viewed with a strobe light
to within 62 % of the maximum force being used.
to slow the apparent motion of the deflection.
9. Test Termination
8. Procedure
9.1 Continue the test until the specimen fails or until a
8.1 Specimen Test Orientation—The angle between the
predetermined number of cycles has been applied to the
distal stem axis and the line of load application shall be 10 6
specimen. Failure should be defined as a complete separation,
1° %. An example of a method to accomplish mounting the
or exceeding of a deflection limit on a test machine. In
stem at the desired angle is given in Appendix X2.
reporting results, state the criteria selected for defining failure
8.2 Specimen Mounting:
andthenumberofcyclesshownasthepredeterminedrunoutof
8.2.1 Maintain the stem Reference Angle X within a range
the test. Discard the data for a specific sample if the grouting
of 61° over a test group.
agent fractured prior to test completion.
8.2.2 Maintain the unsupported stem length at 62 mm.
8.2.3 No relative motion between the prosthesis and the
10. Report
grouting agent shall be permitted during hardening of the
10.1 Report the fatigue test specimens, procedures, and
grouting agent.
results in accordance with Recommended Practice E468.
8.2.4 The surface of the grouting agent at the cantilever
...