ASTM F2722-15

Standard Practice for Evaluating Mobile Bearing Knee Tibial Baseplate Rotational Stops

SIGNIFICANCE AND USE
4.1 Fundamental aspects of this practice include the use of dynamic rotational force and motion representative of the human knee joint during an activity of daily living (deep flexion) and the effect of these forces and motions on the design features which stop or limit rotation in a mobile bearing knee design.  
4.2 This test is required if rotational stops are designed to limit motion to ±20° or less; or there are other resistances to rotational motion with this ±20° range. In some instances, the rotational displacement could occur in both the inferior and superior interfaces.
SCOPE
1.1 This practice covers a laboratory-based  in vitro method for evaluating the mechanical performance of materials and devices being considered for replacement of the tibio-femoral joint in human knee joint replacement prostheses in mobile bearing knee systems.  
1.2 Mobile bearing knee systems permit internal external rotation to take place on one or both articulating surfaces. Some designs place physical limits or stops to the amount of rotation. Other designs may have increases of a resistance force with increases in rotation.  
1.3 Although the methodology describes attempts to identify physiologically relevant motions and force conditions, the interpretation of results is limited to an in vitro comparison between mobile bearing knee designs and their ability to maintain the integrity of the rotational stop feature and tibial bearing component under the stated test conditions.  
1.4 This practice is only applicable to mobile knee tibial systems with a rotational stop.  
1.5 The values stated in SI units are regarded as 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 and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 14-Jan-2015
• ICS: 11.040.40 - Implants for surgery, prosthetics and orthotics
• Technical Committee: F04 - Medical and Surgical Materials and Devices
• Drafting Committee: F04.22 - Arthroplasty

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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: F2722 − 15
Standard Practice for
Evaluating Mobile Bearing Knee Tibial Baseplate Rotational
1
Stops
This standard is issued under the fixed designation F2722; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 3. Terminology
1.1 This practice covers a laboratory-based in vitro method 3.1 Definitions:
for evaluating the mechanical performance of materials and
3.1.1 bearing axis—thelineconnectingthelowestpointson
devices being considered for replacement of the tibio-femoral
both the lateral and medial condyles of the superior surface of
joint in human knee joint replacement prostheses in mobile
the mobile bearing.
bearing knee systems.
3.1.2 inferior articulating interfaces—any interface in
1.2 Mobile bearing knee systems permit internal external
which relative motion occurs between the underside of the
rotation to take place on one or both articulating surfaces.
mobile bearing component and the tibial tray.
Some designs place physical limits or stops to the amount of
3.1.3 mobile bearing—the component between fixed femo-
rotation.Otherdesignsmayhaveincreasesofaresistanceforce
ral and tibial knee components with an articulating surface on
with increases in rotation.
both the inferior and superior sides.
1.3 Although the methodology describes attempts to iden-
3.1.4 mobile bearing knee system—a knee prosthesis
tify physiologically relevant motions and force conditions, the
system, comprised of a tibial component, a mobile bearing
interpretation of results is limited to an in vitro comparison
component that can rotate or rotate and translate relative to the
between mobile bearing knee designs and their ability to
tibial component, and a femoral component.
maintain the integrity of the rotational stop feature and tibial
3.1.5 neutral point—midpoint of the bearing axis.
bearing component under the stated test conditions.
3.1.6 rotational stop—a feature that prevents relative rota-
1.4 This practice is only applicable to mobile knee tibial
tion between two articulating joint surfaces beyond a specific
systems with a rotational stop.
angle of rotation or creates resistance to rotation beyond a
1.5 The values stated in SI units are regarded as standard.
specific angel of rotation.
1.6 This standard does not purport to address all of the
3.1.7 superior articulating interfaces—any interface in
safety concerns, if any, associated with its use. It is the
whichrelativemotionoccursbetweenthetopsideofthemobile
responsibility of the user of this standard to establish appro-
bearing component and the femoral bearing component.
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
4. Significance and Use
2. Referenced Documents
4.1 Fundamental aspects of this practice include the use of
2
2.1 ASTM Standards:
dynamic rotational force and motion representative of the
F2083Specification for Knee Replacement Prosthesis
human knee joint during an activity of daily living (deep
F2003Practice for Accelerated Aging of Ultra-High Mo-
flexion) and the effect of these forces and motions on the
lecular Weight Polyethylene after Gamma Irradiation in
designfeatureswhichstoporlimitrotationinamobilebearing
Air
knee design.
4.2 This test is required if rotational stops are designed to
1
ThispracticeisunderthejurisdictionofASTMCommitteeF04onMedicaland
limit motion to 620° or less; or there are other resistances to
Surgical Materials and Devices and is the direct responsibility of Subcommittee
F04.22 on Arthroplasty. rotational motion with this 620° range. In some instances, the
Current edition approved Jan. 15, 2015. Published February 2015. Originally
rotational displacement could occur in both the inferior and
approved in 2008. Last previous edition approved in 2008 as F2722-08. DOI:
superior interfaces.
10.1520/F2722-15.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
5. Apparatus and Materials
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. 5.1 Component Configurations:
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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F2722 − 15
5.2.4 If the rotational stop geometries for internal and
external rotation are non-symmetrical, both the internal and
external rotational stops should be tested. The same sample
may be used for both tests if the results of the first test do not
cause any damage that could
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: F2722 − 08 F2722 − 15
Standard Test Method Practice for
Evaluating Mobile Bearing Knee Tibial Baseplate Rotational
1
Stops
This standard is issued under the fixed designation F2722; 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 practice covers a laboratory-based in vitro method for evaluating the mechanical performance of materials
and devices being considered for replacement of the tibio-femoral joint in human knee joint replacement prostheses in mobile
bearing knee systems.
1.2 Mobile bearing knee systems permit internal external rotation to take place on one or both articulating surfaces. Some
designs place physical limits or stops to the amount of rotation. Other designs may have increases of a resistance force with
increases in rotation.
1.3 Although the methodology describes attempts to identify physiologically relevant motions and force conditions, the
interpretation of results is limited to an in vitro comparison between mobile bearing knee designs and their ability to maintain the
integrity of the rotational stop feature and tibial bearing component under the stated test conditions.
1.4 This test method practice is only applicable to mobile knee tibial systems with a rotational stop.
1.5 The values stated in SI units are regarded as 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 and health practices and determine the applicability of regulatory
limitations prior to use.
2. Referenced Documents
2
2.1 ASTM Standards:
F2083 Specification for Knee Replacement Prosthesis
F2003 Practice for Accelerated Aging of Ultra-High Molecular Weight Polyethylene after Gamma Irradiation in Air
3. Terminology
3.1 Definitions:
3.1.1 bearing axis—the line connecting the lowest points on both the lateral and medial condyles of the superior surface of the
mobile bearing.
3.1.2 inferior articulating interfaces—any interface in which relative motion occurs between the underside of the mobile
bearing component and the tibial tray.
3.1.3 mobile bearing—the component between fixed femoral and tibial knee components with an articulating surface on both
the inferior and superior sides.
3.1.4 mobile bearing knee system—a knee prosthesis system, comprised of a tibial component, a mobile bearing component that
can rotate or rotate and translate relative to the tibial component, and a femoral component.
3.1.5 neutral point—midpoint of the bearing axis.
3.1.6 rotational stop—a feature that prevents relative rotation between two articulating joint surfaces beyond a specific angle
of rotation or creates resistance to rotation beyond a specific angel of rotation.
1
This test method practice 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 June 1, 2008Jan. 15, 2015. Published July 2008February 2015. Originally approved in 2008. Last previous edition approved in 2008 as F2722-08.
DOI: 10.1520/F2722-08.10.1520/F2722-15.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. 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
1

---------------------- Page: 1 ----------------------
F2722 − 15
3.1.7 superior articulating interfaces—any interface in which relative motion occurs between the topside of the mobile bearing
component and the femoral bearing component.
4. Significance and Use
4.1 Fundamental aspects of this test method practice include the use of dynamic rotational force and motion representative of
the human knee joint during an activity of daily living (deep flexion) and the effect of these forces and motions on the design
features which stop or limit rotation in a mobile bearing knee design.
4.2 This test is required if rotational stops are designed to limit motion to 620° or less; or there are other resistances to rotational
motion with this 620° range. In som
...