ASTM F2582-20

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Designation: F2582 − 14 F2582 − 20
Standard Test Method for
Impingement of Acetabular ProsthesesDynamic
Impingement Between Femoral and Acetabular Hip
Components
This standard is issued under the fixed designation F2582; 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
1.1 This test method covers a procedure to evaluate acetabular component fatigue, deformation, and wear and femoral head
assembly dislocation under dynamic impingement conditions.simulate dynamic impingement between femoral and acetabular
components in a hip replacement; the subsequent qualitative assessment of damage modes (as outlined in 8.2); and, if necessary,
quantitative assessment of changes in modular component attachment strength.
1.2 This test method can be used to evaluate single-piece acetabular prostheses, modular prostheses, and constrained prostheses
impingement between femoral components and the following: single-piece, modular, semi-constrained, bipolar, constrained, or
dual mobility acetabular components, manufactured from polymeric, metallic, or ceramic materials.
1.3 The values stated in SI units are regarded as the standard.
1.4 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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.5 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.
2. Referenced Documents
2.1 ASTM Standards:
E4 Practices for Force Verification of Testing Machines
E467F1820 Practice for Verification of Constant Amplitude Dynamic Forces in an Axial Fatigue Testing SystemTest Method for
Determining the Forces for Disassembly of Modular Acetabular Devices
F2003 Practice for Accelerated Aging of Ultra-High Molecular Weight Polyethylene after Gamma Irradiation in Air
F2009 Test Method for Determining the Axial Disassembly Force of Taper Connections of Modular Prostheses
F2033 Specification for Total Hip Joint Prosthesis and Hip Endoprosthesis Bearing Surfaces Made of Metallic, Ceramic, and
Polymeric Materials
F2091 Specification for Acetabular Prostheses
This test method is under the jurisdiction of ASTM Committee F04 on Medical and Surgical Materials and Devices and is the direct responsibility of Subcommittee
F04.22 on Arthroplasty.
Current edition approved April 1, 2014Nov. 15, 2020. Published April 2014December 2020. Originally approved in 2008. Last previous edition approved in 20082014
as F2582 – 08.14. DOI: 10.1520/F2582-14.10.1520/F2582-20.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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2.2 ISO Standards:
ISO 7206-1 Implants for Surgery – Partial and Total Hip Joint Prostheses – Part 1: Classification and Designation of Dimensions
ISO 7206-6 Implants for Surgery – Partial and Total Hip Joint Prostheses – Part 6: Endurance Properties Testing and
Performance Requirements of Neck Region of Stemmed Femoral Components
ISO 14242-1 Implants for Surgery – Wear of Total Hip-Joint Prostheses – Part 1: Loading and Displacement Parameters for
Wear-Testing Machines and Corresponding Environmental Conditions for Test
ISO 14242-2 Implants for Surgery – Wear of Total Hip-Joint Prostheses – Part 2: Methods of Measurement
ISO 21535 Non-Active Surgical Implants – Joint Replacement Implants – Specific Requirements for Hip-Joint Replacement
Implants
2.3 FDA Document:
21 CFR 888.6 Degree of Constraint
3. Terminology
3.1 Definitions:
3.1.1 component separation—the disruption of a connection between components. May be stable or unstable.
3.1.2 dislocation—the loss of normal physical contact between opposing components, usually indicated by large separation and
a loss of stability.
3.1.1 femoral head—convex spherical bearing member for articulation with the natural acetabulum or prosthetic acetabulum.
3.1.2 impingement—the point at which two opposing components collide to restrict motion.
3.1.5 joint reaction force—the force directed normal to the entry diameter of the acetabular prosthesis (see ISO 7206-1).
3.1.3 locking mechanism—the pieces of various components that contribute to the fixing of one component to another.
3.1.4 range of motion—the effective pattern of motion limited by impingement. In one plane this is measured from one
impingement point to the opposite impingement point.
3.1.8 subluxation—partial dislocation.
3.1.5 The following classification by degree of constraint is suggested for all total joint prostheses, including total hip replacement
systems based on the concepts adopted by the U.S. Food and Drug Administration (21 CFR 888.6; see 2.3).
3.1.5.1 Constrained—A “constrained” joint prosthesis is used for joint replacement and prevents dislocation of the prosthesis in
more than one anatomic plane and consists of either a single, flexible, across-the-joint component or more than one component
linked together or affined.
3.1.5.2 Semi-Constrained—A “semi-constrained” joint prosthesis is used for joint replacement and limits translation and rotation
of the prosthesis in one or more planes via the geometry of its articulating surfaces. It has no across-the-joint linkage.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 compressive load—the force directed normal to the entry diameter of the acetabular prosthesis (see ISO 7206-1).
4. Summary of Test Method
4.1 Acetabular prostheses Femoral and acetabular components are evaluated for fatigue, deformation, and wear under
repeatedfatigue fracture, deformation, delamination, wear, and chipping (ceramic components) under dynamic impingement
conditions. Modular acetabular prostheses prosthesis designs should be evaluated for additional failure mechanisms including
Available from International Organization for Standardization (ISO), 1, ch. de la Voie-Creuse, CP 56, CH-1211 Geneva 20, Switzerland, http://www.iso.org.American
National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http://www.ansi.org.
McKellop, H. A., “The Lexicon of Polyethylene Wear in Artificial Joints,” Biomaterials, Vol 28, 2007, pp. 5049–5057 (Definition of wear modes).Available from U.S.
Food and Drug Administration (FDA), 10903 New Hampshire Ave., Silver Spring, MD 20993, http://www.fda.gov.
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separation, loosening, fracture, and deformationdamage mechanisms affecting any component or locking mechanism. Examples of
damage modes for modular acetabular prosthesis designs include dissociation and loosening of any component or locking
mechanism, or both.
4.2 This test method can be used to evaluate dynamic characteristics. Various joint reaction forces and impingements can be
applied in order to simulate known clinical conditions.
5. Significance and Use
5.1 This test method should be used to evaluate and compare acetabular prostheses different femoral and acetabular prosthesis
designs to assess the relative degree of constraint for the prosthesis and the damage tolerance under controlled laboratory
conditions.
5.2 Although the methodology described attempts to identify physiologically relevant motions and loading conditions, the
interpretation of results is limited to an inin-vitro vitro comparison between different femoral and acetabular prosthesis designs
regarding constraint and their ability to resist impingement fatigue, wear, deformation, anddamage modes (defined in
8.2dislocation) under the stated test conditions.
6. Apparatus for Impingement
6.1 One axis shall be capable of applying a constant joint reactioncompressive load force for static loading.
6.2 Three motion axes shall be capable of controlling and monitoring angular displacement.
6.3 The equipment may be electromechanical, servo-hydraulicservohydraulic, or other, as long as it meets the requirements of
Practices E4 and E467for force verification.
6.4 The joint reaction force compressive load shall be applied through unconstrained fixturing that allows for the separation of the
acetabular prosthesis from the femoral prosthesis during the impingement and dislocation test. See Fig. 1 for the test principle. The
acetabular prosthesis is allowed to move freely in the horizontal plane but is constrained for rotation around the load axis. For hip
simulators that do not meet these requirements, the deviations from the standardized test setup shall be justified.
NOTE 1—For dual mobility components, the mobile component might be fixated by means of a rotational stop to allow for impingement testing.
7. Sampling and Test Specimens
7.1 All acetabular and femoral components shall be representative of implant quality products. This shall include any sterilization
processes if the sterilization may affect the results.
7.2 A minimum of three samples shall be tested to determine Worst-case specimen(s) shall be determined and justified for all
conditionally acceptable damage modes (see 8.2the impingement wear. Three additional samples should be used as reference
samples without impingement in order to provide a comparison to the amount of mode 1 ). The worst-case specimen(s) may vary
FIG. 1 Principle of the Test Set-UpSetup
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by damage mode. Ensure all components in the test are considered, including aspects like head offset, stem geometry, surface
finish, and material and acetabular component(s) geometry, surface finish, and material. Deformation and wear of components may
occur during testing, and if so, will be continually changing with the potential of accentuated change at the times of component
repositioning. In consideration of the unknown geometries, calculation of contact stresses and other stresses in the components (for
example, stress in locking mechanism region) that are needed for worst-case analysis should consider the as-manufactured (not
deformed) geometry of the components. Consideration of overall worst case for each damage mode should consider how
deformation and wear that would otherwise occur if the primary samples were not impinging.will contribute to overall worst case,
and will likely need to be based on evaluation or experience.
NOTE 2—Modeling the neck-rim contact using a Finite Element Method (FEM) to determine maximum stress configuration is one possible technique to
support the worst-case analysis.
NOTE 3—Worst-case considerations may include contact geometry, material finish, thinnest acetabular component(s), components with lowest initial
locking strength, components exhibiting direct metal-on-metal contact, and component materials with lowest strength.
7.3 A minimum of three samples shall be tested.
7.4 Precondition the polymeric specimens according to Practice F2003 (artificial aging).aging) unless there is evidence that the
polymeric specimens are generally resistant to aging.
NOTE 4—The acetabular and femoral prostheses should have freedom to move relative to each other in the plane perpendicular to the compressive load.
Flexion-extension (FE), abduction-adduction (AA), and internal-external (IE) rotations are relative motions between the acetabular and femoral
prostheses. Implant in regular (left) and impingement (right) position.
NOTE 5—Rotation around the load axis is constrained. This can be achieved by a xy-table.
NOTE 6—Some simulator designs may allow for xy-translation of the femoral prosthesis. In principle this setup is sufficient for testing according to this
standard, but great care must be taken to achieve the correct loading conditions.
7.4 Precondition the specimens according to ISO 14242-2 (soaking).
8. Procedure
8.1 Test Procedure:
8.1.1 WeighAssemble the acetabular inserts as described by ISOprosthesis according to Test Method F182014242-2. (if
applicable) and the femoral prothesis according to Test Method F2009 (if applicable).
8.1.2 Measure the original (unworn) geometry of the impingement section of the acetabular insert.
8.1.2 See Fig. 1 for a schematic representation of the test setup.
NOTE 7—A worst-case test setup for bipolar components is one in which the outer bipolar component articulation is locked in rotation (A/P, M/L, and
polar axes) to simulate soft tissue impeding component mobility, such that there is restricted relative motion between the outer articulation and the
acetabulum.
NOTE 8—Worst-case test setups for dual mobility components include both (1) locking the outer dual mobility articulation to AP and ML rotations; and
(2) allowing the outer dual mobility articulation to freely move around all axes to achieve impingement contact between the femoral head (skirted) or
neck of the femoral stem and the acetabular liner or shell. For (2), impingement at the outer dual mobility articulation is not intended. This component
can be locked to avoid impingement if necessary. Include in the report which worst-case test setup(s) were evaluated and, if one is omitted, a rationale
should be provided.
8.1.3 Mount the acetabular prosthesis with the entry diameter plane orthogonal to the direction on the main joint reaction force
compressive load imposed by the simulator.
8.1.4 Mount the femoral prosthesis separately, such that the simulator actuators allow for relative motion with the acetabular
component, providing flexion/extension, abduction-adduction,abduction/adduction, and internal-external rotation. The femoral
component assembly shall consist of a femoral head and stem neck region for the minimum length that may contact the acetabular
component.
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8.1.5 See Fig. 2 for the definition of the coordinate system. The rotation axis is aligned with the neck of the femoral component
and the extension axis is in the frontal plane as shown in Fig. 2 (see X1.8). The coordinate system is stationary in relation to the
acetabular component. The sequence of angular transformation (Euler angles) is abduction-extension-rotation. For a test frame that
does not generate the Euler sequence by its mechanical setup (that is, the extension actuator is moved by the abduction frame and
the rotation actuator is moved by the extension frame), the motions described in Fig. 3 have to be transformed.
NOTE 9—The alignment of the cup versus the compressive load is intended to be constant. The impingement forces generated by simulators that do move
the cup versus the compressive load force must be analyzed to ensure that the loading conditions as described by this standard are generated.
NOTE 10—The use of quaternions has been found helpful for coordinate transformation.
8.1.6 Adjust the simulator actuators for the hip assembly to have zero internal/external rotation and zero flexion/extension.
NOTE 11—Computer analysis as well as range of motion testing as described by ISO 21535 might support the adjustment of the reference position.
8.1.7 Apply a constant joint reaction force compressive load of 600 N.
8.1.8 Rotate a subset of three test assemblies around the center of the femoral head under angular displacement control in
abduction motion until impingement in the direction of rotation of these test samples occurs. With this starting point and the
abduction motion described in Fig. 2, impingement will occur throughout the entire test cycle.
8.1.8 Adjust the other subset (optional) of three assemblies (control samples) in a position which allows for a minimum of 5° of
abduction motion before contactingRotate the test assemblies around the center of the femoral head under angular displacement
control in abduction motion until impingement in the direction of rotation of these test samples occurs. With this starting point and
the abduction motion described in Fig. 3the acetabular component., impingement will occur throughout the entire first test cycle.
NOTE 12—The contact conditions shall represent the worst cast worst-cast in-vivo situation. Internal/external rotation or flexion/extension of the stem, or
both, shall be considered.
NOTE 13—Computer models may be used to evaluate the worst-case impingement.
NOTE 14—Testing of constrained prostheses will require additional mechanical or electronic systems, or both, to limit the test load to the joint reaction
force compressive load of
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