ASTM F1820-97

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

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-Oct-1997
• Technical Committee: F04 - Medical and Surgical Materials and Devices
• Drafting Committee: F04.22 - Arthroplasty

Relations

• Replaced By: ASTM F1820-97(2003) - Standard Test Method for Determining the Axial Disassembly Force of a Modular Acetabular Device
• 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-Oct-1997
• Referred By: ASTM F1814-22 - Standard Guide for Evaluating Modular Hip and Knee Joint Components
• Effective Date: 10-Oct-1997
• Referred By: ASTM F2582-20 - Standard Test Method for Dynamic Impingement Between Femoral and Acetabular Hip Components
• Effective Date: 10-Oct-1997
• 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-Oct-1997
• Referred By: ASTM F1378-18e1 - Standard Specification for Shoulder Prostheses
• Effective Date: 10-Oct-1997
• Referred By: ASTM F2091-15 - Standard Specification for Acetabular Prostheses (Withdrawn 2023)
• Effective Date: 10-Oct-1997

Standards Content (Sample)

NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: F 1820 – 97
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 The acetabular shell may be either solid or contain holes for
fixation, or contain a hole for instrumentation, or all of these.
1.1 This test method covers a standard methodology by
3.1.3 locking mechanism—any structure, design feature or
which to measure the attachment strength between the modular
combination thereof, that provides mechanical resistance to
acetabular shell and liner. Although the methodology described
movement between the liner and shell.
does not replicate physiological loading conditions, it has been
described as means of comparing integrity of various locking
4. Summary of Test Method
mechanisms.
4.1 The axial disassembly of an acetabular device test
1.2 This standard does not purport to address all of the
method provides a means to measure the axial locking strength
safety concerns, if any, associated with its use. It is the
of the acetabular liner for modular acetabular devices.
responsibility of the user of this standard to establish appro-
4.2 Following proper assembly of the acetabular liner in an
priate safety and health practices and determine the applica-
acetabular shell, the assembled device is attached to a fixture
bility of regulatory limitations prior to use.
such that the cup opening is facing downward. The acetabular
2. Referenced Documents shell is supported and an axial force is applied to the acetabular
liner until it disengages. The load required to disengage the
2.1 ASTM Standards:
acetabular liner from the acetabular shell is recorded. The
E 4 Practices for Force Verification of Testing Machines
acetabular liner should only be tested one time; however, the
3. Terminology
acetabular shell may used more than once if no damage to the
locking mechanism has occurred.
3.1 Definitions of Terms Specific to This Standard:
3.1.1 acetabular liner—portion of the modular acetabular
5. Significance and Use
device with an internal hemispherical socket intended to
5.1 This test method is intended to help assess the axial
articulate with the head of a femoral prosthesis. The external
locking strength of the acetabular liner in a modular shell when
geometry of this component interfaces with the acetabular shell
subjected to a tensile loading condition. Additional means of
through a locking mechanism which may be integral to the
evaluating the locking mechanisms of modular acetabular
design of the liner and shell or may rely upon additional
devices may be appropriate depending upon the design of the
components (for example, metal ring, screws, etc.)
device (that is, lever-out, torsional strength, fatigue, etc.).
3.1.2 acetabular shell—the external, hollow structure (usu-
5.2 This test method may not be appropriate for all implant
ally metal) that provides additional mechanical support or
applications. The user is cautioned to consider the appropriate-
reinforcement for an acetabular liner and whose external
ness of the method in view of the materials and design being
features interface directly with the bones of the pelvic socket
tested and their potential application.
(for example, through bone cement, intimate press-fit, porous
5.3 While this test method may be used to measure the force
ingrowth, integral screw threads, anchoring screws, pegs, etc.).
required to disengage modular acetabular devices, comparison
of such data for various device designs must take into
This test method is under the jurisdiction of ASTM Committee F-4 on Medical consideration the size of the implant and the type of locking
and Surgical Materials and Devicesand is the direct responsibility of Subcommittee
mechanism evaluated. The location of the locking mechanism
F04.22on Arthroplasty.
relative to the load application may be dependent upon the size
Current edition approved Oct. 10, 1997. Published April 1998.
and design of the acetabular device. In addition, the locking
Tradonsky M.D., Steve, et al, “A Comparison of the Disassociation Strength of
Modular Acetabular Components,” Clinical Orthopaedics and Related Research,
mechanism itself may vary with size, particularly if the design
Number 296, November 1993.
is circumferential in nature (for example, larger diameter
Annual Book of ASTM Standards, Vol 03.01.
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NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
F1820–97
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
shell while allowing the acetabular liner to be freely disas- 8. Procedure
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 placed in a fixture similar to that described in Fig. 1,
acetabular shell.
that is, a fixture that will support the acetabular shell wit
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