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ASTM F2996-13

(Practice)

Standard Practice for Finite Element Analysis (FEA) of Non-Modular Metallic Orthopaedic Hip Femoral Stems

Standard Practice for Finite Element Analysis (FEA) of Non-Modular Metallic Orthopaedic Hip Femoral Stems

SIGNIFICANCE AND USE
3.1 This practice is applicable to the calculation of stresses seen on a femoral hip stem when loaded in a manner described in ISO 7206-4 (2010). This method can be used to establish the worst case size for a particular implant. When stresses calculated using this practice were compared to the stresses measured from physical strain gauging techniques performed at two laboratories using two different methods, the results correlated to within 8 %.
SCOPE
1.1 This practice establishes requirements and considerations for the numerical simulation of non-modular (that is, limited to monolithic stems with only a femoral head / trunnion taper interface) metallic orthopaedic hip stems using Finite Element Analysis (FEA) techniques for the estimation of stresses and strains. This standard is only applicable to stresses below the yield strength, as provided in the material certification.  
1.2 Purpose—This practice establishes requirements and considerations for the development of finite element models to be used in the evaluation of non-modular metallic orthopaedic hip stem designs for the purpose of prediction of the static implant stresses and strains. This procedure can be used for worst case assessment within a family of implant sizes to provide efficiencies in the amount of physical testing to be conducted. Recommended procedures for performing model checks and verification are provided to help determine if the analysis follows recommended guidelines. Finally, the recommended content of an engineering report covering the mechanical simulation is presented.  
1.3 Limits—This practice is limited in discussion to the static structural analysis of non-modular metallic orthopaedic hip stems (which excludes the prediction of fatigue strength).  
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.5 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
14-Jul-2013
ICS
11.040.40 - Implants for surgery, prosthetics and orthotics
Technical Committee
F04 - Medical and Surgical Materials and Devices
Drafting Committee
F04.22 - Arthroplasty
Current Stage
Ref Project

Relations

Replaced By
ASTM F2996-20 - Standard Practice for Finite Element Analysis (FEA) of Non-Modular Metallic Orthopaedic Hip Femoral Stems
Effective Date
15-Jun-2020
Referred By
ASTM F2068-15 - Standard Specification for Femoral Prostheses—Metallic Implants (Withdrawn 2023)
Effective Date
15-Jul-2013

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ASTM F2996-13 - Standard Practice for Finite Element Analysis (FEA) of Non-Modular Metallic Orthopaedic Hip Femoral StemsASTM F2996-13 - Standard Practice for Finite Element Analysis (FEA) of Non-Modular Metallic Orthopaedic Hip Femoral Stems
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ASTM F2996-13 - Standard Practice for Finite Element Analysis (FEA) of Non-Modular Metallic Orthopaedic Hip Femoral Stems
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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: F2996 − 13
Standard Practice for
Finite Element Analysis (FEA) of Non-Modular Metallic
1
Orthopaedic Hip Femoral Stems
This standard is issued under the fixed designation F2996; 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 2. Referenced Documents
2
1.1 This practice establishes requirements and consider- 2.1 ISO Standards:
ISO 7206-4 (2010) Implants for Surgery—Partial and Total
ations for the numerical simulation of non-modular (that is,
limitedtomonolithicstemswithonlyafemoralhead/trunnion HipJointProstheses—Part4:DeterminationofEndurance
Properties and Performance of Stemmed Femoral Com-
taper interface) metallic orthopaedic hip stems using Finite
Element Analysis (FEA) techniques for the estimation of ponents
stresses and strains. This standard is only applicable to stresses
3. Significance and Use
below the yield strength, as provided in the material certifica-
3.1 This practice is applicable to the calculation of stresses
tion.
seen on a femoral hip stem when loaded in a manner described
1.2 Purpose—This practice establishes requirements and
in ISO 7206-4 (2010).This method can be used to establish the
considerations for the development of finite element models to
worst case size for a particular implant. When stresses calcu-
be used in the evaluation of non-modular metallic orthopaedic
lated using this practice were compared to the stresses mea-
hip stem designs for the purpose of prediction of the static
sured from physical strain gauging techniques performed at
implant stresses and strains. This procedure can be used for
two laboratories using two different methods, the results
worst case assessment within a family of implant sizes to
correlated to within 8 %.
provide efficiencies in the amount of physical testing to be
conducted. Recommended procedures for performing model
4. Geometric Data
checks and verification are provided to help determine if the
4.1 Finite element models are based on a geometric repre-
analysis follows recommended guidelines. Finally, the recom-
sentation of the device being studied. The source of the
mendedcontentofanengineeringreportcoveringthemechani-
geometricdetailscanbeobtainedfromdrawings,solidmodels,
cal simulation is presented.
preliminary sketches, or any other source consistent with
1.3 Limits—This practice is limited in discussion to the
defining the model geometry. In building the finite element
static structural analysis of non-modular metallic orthopaedic
model, certain geometric details may be omitted from the
hip stems (which excludes the prediction of fatigue strength).
orthopaedic implant geometry shown in the CAD model if it is
determined that they are not relevant to the intended analysis.
1.4 The values stated in SI units are to be regarded as
Engineering judgment shall be exercised to establish the extent
standard. No other units of measurement are included in this
of model simplification and shall be justified.
standard.
4.2 It is most appropriate to consider the “worst case” stress
1.5 This standard does not purport to address all of the
condition for the orthopaedic implant being simulated. The
safety concerns, if any, associated with its use. It is the
“worst case” shall be determined from all relevant engineering
responsibility of the user of this standard to establish appro-
considerations, such as stem geometry, dimensions, and head
priate safety and health practices and determine the applica-
offset. If finite element analysis is being used for determining
bility of regulatory limitations prior to use.
the worst case, then the worst case head offset may not be
known. It may be necessary to run several variants of head
1
ThispracticeisunderthejurisdictionofASTMCommitteeF04onMedicaland
offset, in order to determine this.
Surgical Materials and Devices and is the direct responsibility of Subcommittee
F04.22 on Arthroplasty.
2
Current edition approved July 15, 2013. Published August 2013. DOI: 10.1520/ Available from International Organization for Standardization (ISO), 1, ch. de
F2996-13. la Voie-Creuse, CP 56, CH-1211 Geneva 20, Switzerland, http://www.iso.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
F2996 − 13
5. Material Properties to approximate the loading conditions that simulate the worst
case head offset, which may be determined via an iterative
5.1 The required material properties for input into an FEA
process. This approximation should be reported if performed.
model for the calc
...

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A1.1 Significance and Use
A1.1.1 This test method is used to measure the torsional yield strength, maximum torque, and breaking angle of the bone screw under standard conditions. The results obtained in this test method are not intended to predict the torque encountered while inserting or removing a bone screw in human or animal bone. This test method is intended only to measure the uniformity of the product tested or to compare the mechanical properties of different, yet similarly sized, products.
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1.6 This standard may involve the use of hazardous materials, operations, and equipment. 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
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4.1 The purpose of this test guide is to provide load profile information on how one could test a total knee replacement in order to evaluate in vitro its function and wear during several types of knee motions as described in 4.2 and 4.3.  
4.2 This test guide may help characterize the magnitude and location of implant wear as an implant is repetitively moved according to specified load and displacement waveforms.  
4.3 This test guide may also help characterize the functional limitations of a total knee replacement as its motion is guided by these waveforms. These limitations may be observed as impingement, subluxation, or high loading in the soft tissue constraints, whether they are represented physically or virtually.  
4.4 The motions and load conditions in vivo will, in general, differ from the load and motions defined in this guide. The results obtained from this guide cannot be used to directly predict in vivo performance. However, this guide is designed to allow for comparisons in performance of different knee designs, when tested under similar conditions.
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1.1 Motion path, load history, and loading modalities all contribute to the wear, degradation, and damage of implanted prosthetics. Simulating a variety of functional activities promises more realistic testing for wear and damage mode evaluation. Such activities are often called activities of daily living (ADLs). ADLs identified in the literature include walking, stair ascent and descent, sit-to-stand, stand-to-sit, squatting, kneeling, cross-legged sitting, into bath, out of bath, turning, and cutting motions (1-7).2 Activities other than walking gait often involve an extended range of motion and higher imposed loading conditions, which have the ability to cause damage and modes of failure other than normal wear (8-10).  
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1.6 This document does not address the assessment or measurement of damage modes, or wear or failure of the prosthetic device.  
1.7 This document is a guide. As defined by ASTM in their “Form and Style for ASTM Standards” book in section C15.2, “A standard guide is a compendium of information or series of options that does not recommend a specific course of action. Guides are intended ...

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5.2 This guide makes suggestions of what high demand test features may need to be added to an overall high demand wear test regime. The features described here are not meant to be all inclusive. Based on current knowledge they appear to be relevant to adverse conditions that can occur in clinical use.  
5.3 All the test features, both conventional and high demand, could have interactive effects on the wear of the components.
SCOPE
1.1 The objective of this guide is to advise researchers on the possible high demand wear test features that should be included in evaluation of hard-on-hard articulations. This guide makes suggestions for high demand test features that may need to be added to an overall wear test regime. Device articulating components manufactured from other metallic alloys, ceramics, or with coated or elementally modified surfaces without significant clinical use could possibly be evaluated with this guide. However, such materials may include risks and failure mechanisms that are not addressed in this guide.  
1.2 Hard-on-hard hip bearing systems include metal-on-metal (for example, Specifications F75, F799, and F1537; ISO 5832-4, ISO 5832-12), ceramic-on-ceramic (for example, ISO 6474-1, ISO 6474-2, ISO 13356), ceramic-on-metal, or any other bearing systems where both the head and cup components have high surface hardness. An argument has been made that the hard-on-hard THR articulation may be better for younger, more active patients. These younger patients may be more physically fit and expect to be able to perform more energetic activities. Consequently, new designs of hard-on-hard THR articulations may have some implantations subjected to more demanding and longer wear performance requirements.  
1.3 Total Hip Replacement (THR) with metal-on-metal articulations have been used clinically for more than 50 years (1, 2).2 Early designs had mixed clinical results. Eventually they were eclipsed by THR systems using metal-on-polyethylene articulations. In the 1990s the metal-on-metal articulation again became popular with more modern designs (3), including surface replacement.  
1.4 In the 1970s the first ceramic-on-ceramic THR articulations were used. In general, the early results were not satisfactory (4, 5). Improvement in alumina, and new designs in the 1990s improved the results for ceramic-on-ceramic articulations (6).  
1.5 The values stated in SI units are to be regarded as the standard.  
1.6 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.7 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.

  • Guide
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    English language
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  • Guide
    8 pages
    English language
    sale 15% off