ASTM F1820-97(2003)

Standard Test Method for Determining the Axial Disassembly Force of a Modular Acetabular Device

SIGNIFICANCE AND USE
This test method is intended to help assess the axial locking strength of the acetabular liner in a modular shell when subjected to a tensile loading condition. Additional means of evaluating the locking mechanisms of modular acetabular devices may be appropriate depending upon the design of the device (that is, lever-out, torsional strength, fatigue, and so forth).
This test method may not be appropriate for all implant applications. The user is cautioned to consider the appropriateness of the method in view of the materials and design being tested and their potential application.
While this test method may be used to measure the force required to disengage modular acetabular devices, comparison of such data for various device designs must take into consideration the size of the implant and the type of locking mechanism evaluated. The location of the locking mechanism relative to the load application may be dependent upon the size and design of the acetabular device. In addition, the locking mechanism itself may vary with size, particularly if the design is circumferential in nature (for example, larger diameter implants would have a greater area of acetabular shell/acetabular liner interface than a small diameter implant).
SCOPE
1.1 This test method covers a standard methodology by which to measure the attachment strength between the modular acetabular shell and liner. Although the methodology described does not replicate physiological loading conditions, it has been described as means of comparing integrity of various locking mechanisms.
1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 09-Apr-2003
• 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 F1820-97 - Standard Test Method for Determining the Axial Disassembly Force of a Modular Acetabular Device
• Effective Date: 10-Apr-2003
• Replaced By: ASTM F1820-97(2009) - Standard Test Method for Determining the Axial Disassembly Force of a Modular Acetabular Device
• Effective Date: 01-Feb-2009
• Referred By: ASTM F2091-15 - Standard Specification for Acetabular Prostheses (Withdrawn 2023)
• Effective Date: 10-Apr-2003
• Referred By: ASTM F1814-22 - Standard Guide for Evaluating Modular Hip and Knee Joint Components
• Effective Date: 10-Apr-2003
• Referred By: ASTM F1378-18e1 - Standard Specification for Shoulder Prostheses
• Effective Date: 10-Apr-2003
• Referred By: ASTM F3018-17 - Standard Guide for Assessment of Hard-on-Hard Articulation Total Hip Replacement and Hip Resurfacing Arthroplasty Devices
• Effective Date: 10-Apr-2003
• Referred By: ASTM F2582-20 - Standard Test Method for Dynamic Impingement Between Femoral and Acetabular Hip Components
• Effective Date: 10-Apr-2003
• Referred By: ASTM F3090-20 - Standard Test Method for Fatigue Testing of Acetabular Devices for Total Hip Replacement
• Effective Date: 10-Apr-2003

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:F1820–97 (Reapproved 2003)
Standard Test Method for
Determining the Axial Disassembly Force of a Modular
Acetabular Device
This standard is issued under the fixed designation F 1820; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope so forth). The acetabular shell may be either solid or contain
holes for fixation, or contain a hole for instrumentation, or all
1.1 This test method covers a standard methodology by
of these.
which to measure the attachment strength between the modular
3.1.3 locking mechanism—any structure, design feature or
acetabular shell and liner.Although the methodology described
combination thereof, that provides mechanical resistance to
does not replicate physiological loading conditions, it has been
movement between the liner and shell.
described as means of comparing integrity of various locking
mechanisms.
4. Summary of Test Method
1.2 This standard does not purport to address all of the
4.1 The axial disassembly of an acetabular device test
safety concerns, if any, associated with its use. It is the
method provides a means to measure the axial locking strength
responsibility of the user of this standard to establish appro-
of the acetabular liner for modular acetabular devices.
priate safety and health practices and determine the applica-
4.2 Following proper assembly of the acetabular liner in an
bility of regulatory limitations prior to use.
acetabular shell, the assembled device is attached to a fixture
2. Referenced Documents such that the cup opening is facing downward. The acetabular
shell is supported and an axial force is applied to the acetabular
2.1 ASTM Standards:
liner until it disengages. The load required to disengage the
E 4 Practices for Force Verification of Testing Machines
acetabular liner from the acetabular shell is recorded. The
3. Terminology
acetabular liner should only be tested one time; however, the
acetabular shell may used more than once if no damage to the
3.1 Definitions of Terms Specific to This Standard:
locking mechanism has occurred.
3.1.1 acetabular liner—portion of the modular acetabular
device with an internal hemispherical socket intended to
5. Significance and Use
articulate with the head of a femoral prosthesis. The external
5.1 This test method is intended to help assess the axial
geometryofthiscomponentinterfaceswiththeacetabularshell
locking strength of the acetabular liner in a modular shell when
through a locking mechanism which may be integral to the
subjected to a tensile loading condition. Additional means of
design of the liner and shell or may rely upon additional
evaluating the locking mechanisms of modular acetabular
components (for example, metal ring, screws, and so forth).
devices may be appropriate depending upon the design of the
3.1.2 acetabular shell—the external, hollow structure (usu-
device (that is, lever-out, torsional strength, fatigue, and so
ally metal) that provides additional mechanical support or
forth).
reinforcement for an acetabular liner and whose external
5.2 This test method may not be appropriate for all implant
features interface directly with the bones of the pelvic socket
applications. The user is cautioned to consider the appropriate-
(for example, through bone cement, intimate press-fit, porous
ness of the method in view of the materials and design being
ingrowth, integral screw threads, anchoring screws, pegs, and
tested and their potential application.
5.3 While this test method may be used to measure the force
This test method is under the jurisdiction ofASTM Committee F04 on Medical
required to disengage modular acetabular devices, comparison
and Surgical Materials and Devicesand is the direct responsibility of Subcommittee
of such data for various device designs must take into
F04.22on Arthroplasty.
consideration the size of the implant and the type of locking
Current edition approved Apr. 10, 2003. Published June 2003. Originally
approved in 1997. Last previous edition approved in 1997 as F 1820 – 97.
mechanism evaluated. The location of the locking mechanism
Tradonsky M.D., Steve, et al, “AComparison of the Disassociation Strength of
relative to the load application may be dependent upon the size
Modular Acetabular Components,” Clinical Orthopaedics and Related Research,
and design of the acetabular device. In addition, the locking
Number 296, November 1993.
mechanism itself may vary with size, particularly if the design
Annual Book of ASTM Standards, Vol 03.01.
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F1820–97 (2003)
is circumferential in nature (for example, larger diameter unless otherwise reported. The appropriateness of performing
implants would have a greater area of acetabular shell/ multiple tests on the same acetabular shell will depend on the
acetabular liner interface than a small diameter implant). design of the device.The acetabular liner should only be tested
one time; however, the acetabular shell may be used more than
6. Apparatus
once if no damage has occurred to the locking mechanism.
6.1 An apparatus capable of supporting only the acetabular
8. Procedure
shell while allowing the acetabular liner to be freely disas-
sembled from the shell is required. The fixture shall be 8.1 Assemble the liner and shell according to the surgical
constructed so that the line of load application is through the procedure guidelines. Once assembled, the liner shell construct
apex of the shell or is perpendicular to the face center of the should be
...