ASTM F2665-09

Standard Specification for Total Ankle Replacement Prosthesis

SCOPE
1.1 This specification covers total ankle replacement (TAR) prostheses used to provide functioning articulation by employing talar and tibial components that allow for a minimum of 15° of dorsiflexion and 15 to 25° (1) of plantar flexion, as determined by non-clinical testing.  
1.2 Included within the scope of this specification are ankle components for primary and revision surgery with modular and non-modular designs, bearing components with fixed or mobile bearing designs, and components for cemented and/or cementless use.
1.3 This specification is intended to provide basic descriptions of material and prosthesis geometry. In addition, those characteristics determined to be important to in vivo performance of the prosthesis are defined.
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: 31-Jan-2009
• ICS: 11.180.10 - Aids and adaptation for moving
• 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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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:F2665 −09
StandardSpecification for
Total Ankle Replacement Prosthesis
This standard is issued under the fixed designation F2665; 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 F86 Practice for Surface Preparation and Marking of Metal-
lic Surgical Implants
1.1 This specification covers total ankle replacement (TAR)
F90 Specification for Wrought Cobalt-20Chromium-
prostheses used to provide functioning articulation by employ-
15Tungsten-10NickelAlloy for Surgical ImplantApplica-
ing talar and tibial components that allow for a minimum of
2 tions (UNS R30605)
15° of dorsiflexion and 15 to 25° (1) of plantar flexion, as
F136 Specification for Wrought Titanium-6Aluminum-
determined by non-clinical testing.
4Vanadium ELI (Extra Low Interstitial)Alloy for Surgical
1.2 Included within the scope of this specification are ankle
Implant Applications (UNS R56401)
componentsforprimaryandrevisionsurgerywithmodularand
F138 Specification for Wrought 18Chromium-14Nickel-
non-modulardesigns,bearingcomponentswithfixedormobile
2.5Molybdenum Stainless Steel Bar andWire for Surgical
bearing designs, and components for cemented and/or cement-
Implants (UNS S31673)
less use.
F451 Specification for Acrylic Bone Cement
1.3 This specification is intended to provide basic descrip- F562 Specification for Wrought 35Cobalt-35Nickel-
20Chromium-10Molybdenum Alloy for Surgical Implant
tions of material and prosthesis geometry. In addition, those
characteristics determined to be important to in vivo perfor- Applications (UNS R30035)
F563 Specification for Wrought Cobalt-20Nickel-
mance of the prosthesis are defined.
20Chromium-3.5Molybdenum-3.5Tungsten-5Iron Alloy
1.4 The values stated in SI units are to be regarded as
for Surgical Implant Applications (UNS R30563) (With-
standard. No other units of measurement are included in this
drawn 2005)
standard.
F565 PracticeforCareandHandlingofOrthopedicImplants
1.5 This standard does not purport to address all of the
and Instruments
safety concerns, if any, associated with its use. It is the
F648 Specification for Ultra-High-Molecular-Weight Poly-
responsibility of the user of this standard to establish appro-
ethylene Powder and Fabricated Form for Surgical Im-
priate safety and health practices and determine the applica-
plants
bility of regulatory limitations prior to use.
F732 Test Method for Wear Testing of Polymeric Materials
Used in Total Joint Prostheses
2. Referenced Documents
F745 Specification for 18Chromium-12.5Nickel-
2.1 ASTM Standards:
2.5Molybdenum Stainless Steel for Cast and Solution-
F67 Specification for Unalloyed Titanium, for Surgical Im-
Annealed Surgical Implant Applications
plant Applications (UNS R50250, UNS R50400, UNS
F746 Test Method for Pitting or Crevice Corrosion of
R50550, UNS R50700)
Metallic Surgical Implant Materials
F75 Specification for Cobalt-28 Chromium-6 Molybdenum
F748 PracticeforSelectingGenericBiologicalTestMethods
Alloy Castings and Casting Alloy for Surgical Implants
for Materials and Devices
(UNS R30075)
F799 Specification for Cobalt-28Chromium-6Molybdenum
Alloy Forgings for Surgical Implants (UNS R31537,
R31538, R31539)
This specification is under the jurisdiction of ASTM Committee F04 on
F981 Practice for Assessment of Compatibility of Biomate-
Medical and Surgical Materials and Devices and is the direct responsibility of
Subcommittee F04.22 on Arthroplasty. rials for Surgical Implants with Respect to Effect of
Current edition approved Feb. 1, 2009. Published June 2009. DOI: 10.1520/
Materials on Muscle and Bone
F2665-09.
F983 Practice for Permanent Marking of Orthopaedic Im-
The boldface numbers in parentheses refer to a list of references at the end of
plant Components
this standard.
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 last approved version of this historical standard is referenced on
the ASTM website. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F2665−09
F1044 Test Method for Shear Testing of Calcium Phosphate 3.1.4 interlock, n—mechanical design feature used to in-
Coatings and Metallic Coatings crease capture of one component within another and to restrict
F1108 Specification for Titanium-6Aluminum-4Vanadium unwanted displacement between components, that is, compo-
Alloy Castings for Surgical Implants (UNS R56406) nent locking mechanism for modular components.
F1147 Test Method for Tension Testing of Calcium Phos-
3.1.5 plantar flexion, n—rotation of the tibial component
phate and Metallic Coatings
toward the posterior talar surface.
F1160 Test Method for Shear and Bending Fatigue Testing
3.1.6 talar component, n—bearing member fixed to the
of Calcium Phosphate and Metallic Medical and Compos-
talus for articulation with the tibial component. This could be
ite Calcium Phosphate/Metallic Coatings
metallic or from some other suitably hard surface material.
F1223 Test Method for Determination of Total Knee Re-
placement Constraint
3.1.7 radiographic marker, n—a nonstructural wire or bead
F1377 Specification for Cobalt-28Chromium-6Molybdenum
designed to be apparent on X-rays taken after implantation for
Powder for Coating of Orthopedic Implants (UNS
those components that would otherwise not be apparent on
R30075)
such X-rays.
F1472 Specification for Wrought Titanium-6Aluminum-
3.1.8 subluxation, n—instability or partial dislocation
4VanadiumAlloy for Surgical ImplantApplications (UNS
which occurs when the relative translational or rotational
R56400)
motion between the talar and tibial components reaches an
F1537 Specification for Wrought Cobalt-28Chromium-
extreme where the two components would cease to articulate
6Molybdenum Alloys for Surgical Implants (UNS
over the designated low friction bearing surfaces.
R31537, UNS R31538, and UNS R31539)
3.1.9 tibial component, n—fixed or mobile bearing member
F1580 Specification for Titanium and Titanium-6
attached to the tibia for articulation with the talar component,
Aluminum-4 Vanadium Alloy Powders for Coatings of
typically consisting of two major components, a metallic tibial
Surgical Implants
tray and a UHMWPE (see Specification F648) bearing surface.
F1800 Test Method for Cyclic Fatigue Testing of Metal
Tibial Tray Components of Total Knee Joint Replace-
3.1.10 total ankle replacement (TAR), n— prosthetic parts
ments
that substitute for the natural opposing tibial and talar articu-
F1814 Guide for Evaluating Modular Hip and Knee Joint
lating surfaces.
Components
3.1.11 IE rotation, n—rotation of the tibial component
2.2 ISO Standards:
relative to the talar component around the tibial axis. IE
ISO 6474 Implants for Surgery—Ceramic Materials Based
rotation is considered positive when the tibial component
on Alumina
rotates internally (clockwise when viewed proximally on the
ISO 14243–2 Implants for Surgery—Wear of Total Knee-
left ankle). IE rotation is considered negative when the tibial
Joint Prostheses—Part 2: Methods of Measurement
component rotates externally.
2.3 FDA Document:
21 CFR 888.6 Degree of Constraint
4. Classification
21 CFR 888.3110 Ankle Joint Metal/Polymer Semi-
Constrained Cemented Prostheses
4.1 The following classification by degree of constraint is
21 CFR 888.3120 Ankle Joint Metal/Polymer Non- suggested for all total joint prostheses including total ankle
Constrained Cemented Prostheses
replacementsystemsbasedontheconceptsadoptedbytheU.S.
2.4 ANSI/ASME Standard: Food and Drug Administration (see 21 CFR 888.6).
ANSI/ASME B46.1–1995 Surface Texture (Surface
4.1.1 Constrained—A constrained joint prosthesis prevents
Roughness, Waviness, and Lay)
dislocation of the prosthesis in more than one anatomic plane
and consists of either a single, flexible, across the-joint
3. Terminology
component or more than one component linked together or
3.1 Definitions of Terms Specific to This Standard:
affined.
3.1.1 constraint, n—the relative inability of aTAR, inherent
4.1.2 Semi-constrained—A semi-constrained joint prosthe-
to its geometrical and material design, to be further displaced
sis limits translation or rotation, or both to translation and
in a specific direction under a given set of loading conditions.
rotation, of the prosthesis in one or more planes via the
3.1.2 dorsiflexion, n—rotation of the tibial component to-
geometry of its articulating surfaces. Its components have no
wards the anterior talar surface.
across-the-joint linkages.
4.1.3 Non-constrained—A non-constrained joint prosthesis
3.1.3 flexion, n—rotation of the talar component relative to
minimallyrestrictsprosthesismovementinoneormoreplanes.
the tibial component around the medial-lateral axis. Flexion is
Its components have no across-the-joint linkages.
considered positive when it is dorsiflexion, and negative when
it is plantar flexion.
4.2 Currently, most ankle designs are considered either
semi-constrained or non-constrained. Most mobile bearing
Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
ankle components are considered non-constrained. The US
4th Floor, New York, NY 10036, http://www.ansi.org.
government 21 CFR 888.3110 identifies ankle joint metal/
Available from Food and Drug Administration (FDA), 5600 Fishers Ln.,
Rockville, MD 20857, http://www.fda.gov. polymer semi-constrained cemented prosthesis and
F2665−09
21 CFR 888.3120 identifies ankle joint metal/polymer non- narios) to address loss of supporting foundation leading to
constrained cemented prosthesis. potential deformation and/or component fracture.
6.1.1.1 Tibial tray components may be evaluated in a
5. Material manner similar to Test Method F1800, with a loading moment
value chosen to compare with a clinically successful implant,
5.1 All devices conforming to this specification shall be
or justified in other suitable ways for the design being tested)
fabricated from materials with adequate mechanical strength,
(3).Inchoosingtheloadingmoment,boththemomentarmand
durability, corrosion resistance, and biocompatibility.
the load used shall be specified with explanation as to how and
NOTE 1—The choice of materials is understood to be a necessary but why they were chosen. Each of five specimens shall be tested
not totally sufficient assurance of proper function of the device made from
for 10 million cycles with no failure. All tibial components
them.
designated by this specification shall pass this minimum
5.1.1 Mechanical Strength—Various metallic components
requirement.
of total ankle replacement devices have been successfully
6.1.1.2 Tibial bearing surface components shall be fatigue
fabricated from materials, as examples, found in Specifications
tested considering worst-case scenarios to demonstrate that the
F75, F90, F136, F138, F562, F563, F745, F799, F1108, F1377,
component is able to withstand anticipated physiological
F1472, F1537, and F1580. Polymeric bearing components loading conditions and is not susceptible to the failure modes
have been fabricated from UHMWPE, as an example, as
that have been reported in the literature (4-6). The worst case
specified in Specification F648. Porous coatings have been scenarios should take into consideration loads, component
fabricated from example materials specified in Specifications
sizes, thickness of plastic bearing insert, bony support, locking
F67 and F75. Not all of these materials may possess sufficient mechanism, edge loading, misalignments and how these can
mechanical strength for critical, highly stressed components or
affect the individual design.
for articulating surfaces. Conformance of a selected material to 6.1.2 Contactareaandcontactpressuredistributionsmaybe
its standard and successful clinical usage of the material in a
determined at various flexion angles using one of several
previousimplantdesignarenotsufficienttoensurethestrength published methods (7-12) to provide a representation of
ofanimplant.Manufacturingprocessesandimplantdesigncan
stresses applied to the bearing surfaces and to the components.
strongly influence the device’s performance characteristics.
Flexion angles of 0, 610, and 615° are recommended. If the
Therefore, regardless of the material selected, the ankle im-
prosthesis is designed to function at higher angles of either
plant must meet the performance requirements of Section 6.
dorsiflexion or plantar flexion, then it is recommended that
5.1.2 Corrosion Resistance—Materials with limited or no these measurements be continued at 5° increments to the full
history of successful use for orthopaedic implant application range of motion. If these tests are performed, it is important to
shall exhibit corrosion resistance equal to or better than one of maintain consistent test parameters and to evaluate other TAR
the materials listed in 5.1.1 when tested in accordance with prostheses under the same conditions.
Test Method F746. 6.1.3 Range of motion in dorsiflexion and plantar flexion
shallbegreaterthanorequalto15°(each)requiredforwalking
5.1.3 Biocompatibility—Materials with limited or no history
(13-15).These measurements apply to components mounted in
of successful use for orthopaedic implant application shall
neutral alignment in bone or in an anatomically representative
exhibit acceptable biological response equal to or better than
substitute. It is critical to define the location of the neutral
one of the materials listed in 5.1.1 when tested in accordance
alignment position, for example, center of contact areas or
with Practices F748 and F981 for a given application.
patches, in terms of dimensions from outside edges of the
components. The initial positioning or location of the neutral
6. Performance Requirements
alignment point will affect the range of motion values for
6.1 Component Function—Each component for total ankle
certain TAR prostheses. The range of flexion determined from
arthroplasty is expected to function as intended when manu-
non-clinical testing, therefore, can be compromised by mis-
factured in accordance with good manufacturing practices and
alignments in various degrees of freedom. Worst-case scenario
to the requirements of this specification. The components shall
misalignmentsaswellasneutralalignmentshouldbeevaluated
be capable of withstanding static and dynamic physiologic
for dorsi-flexion and plantar flexion range of motion testing.
load
...