ASTM F2068-00

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Designation: F 2068 – 00
Standard Specification for
Femoral Prostheses—Metallic Implants
This standard is issued under the fixed designation F 2068; 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 Tungsten-Nickel Alloy for Surgical Implant Applications
F 136 Specification for Wrought Titanium-6 Aluminum-4
1.1 This specification covers metallic stemmed femoral
Vanadium ELI (Extra-Low Interstitial) Alloy (R56401) for
prostheses used to replace the natural hop joint by means of
Surgical Implant Applications
hemi-arthroplasty or total hip surgical procedures. Prostheses
F 138 Specification for Wrought 18 Chromium-14 Nickel-
for hemi-arthroplasty are intended to articulate with the natural
2.5 Molybdenum Stainless Steel Bar and Wire for Surgical
acetabulum of the patient. Prostheses for total hip replacement
Implants (UNS S31673)
are intended to articulate with prosthetic acetabular cups.
F 562 Specification for Wrought Cobalt-35 Nickel-20
Prostheses may have integral femoral heads or cones designed
Chromium-10 Molybdenum Alloy for Surgical Implant
to accept modular heads.
Applications
1.2 Modular femoral heads, which may be affixed to cones
F 563 Specification for Wrought Cobalt-Nickel-Chromium-
on implants covered by this specification, are not covered by
Molybdenum-Tungsten-Iron Alloy for Surgical Implant
this specification. The mechanical strength, corrosion resis-
Applications
tance, and biocompatibility of the head portions of one-piece
F 620 Specification for Titanium 6Al-4V ELI Alloy Forg-
integral implants are covered by this specification.
ings for Surgical Implants
1.3 Femoral prostheses included within the scope of this
F 745 Specification for 18 Chromium-12.5 Nickel-2.5 Mo-
specification are intended for fixation by press fit between the
lybdenum Stainless Steel for Cast and Solution-Annealed
prosthesis and host bone, the use of bone cement, or through
Surgical Implant Applications
the ingrowth of host bone into a porous coating.
F 746 Test Method for Pitting or Crevice Corrosion of
1.4 Custom femoral prostheses, designed explicitly for a
Metallic Surgical Implant Materials
single patient, are not covered within the scope of this
F 748 Practice for Selecting Generic Biological Test Meth-
specification.
ods for Materials and Devices
1.5 Prostheses incorporating nonmetallic (for example,
F 799 Specification for Cobalt-28 Chromium-6 Molybde-
polymer composite) implants, nonporous bioactive ceramic
num Alloy Forgings for Surgical Implants
coatings, or porous-polymer coatings, are specifically excluded
F 981 Practice for Assessment of Compatibility of Bioma-
from the scope of this specification.
terials for Surgical Implants with Respect to Effect of
1.6 The requirements for modular connections of multicom-
Materials on Muscle and Bone
ponent modular femoral hip prostheses are not covered by this
F 983 Practice for Permanent Marking of Orthopedic Im-
specification.
plant Components
1.7 The values stated in SI units are to be regarded as the
F 1044 Test Method for Shear Testing of Porous Metal
standard.
Coatings
2. Referenced Documents
F 1108 Specification for TI6Al4V Alloy Castings for Sur-
gical Implants
2.1 ASTM Standards:
F 1147 Test Method for Tension Testing of Porous Metal
F 67 Specification for Unalloyed Titanium for Surgical
Coatings
Implant Applications
F 1440 Practice for Cyclic Fatigue Testing of Metallic
F 75 Specification for Cast Cobalt—Chromium-
Stemmed Hip Arthroplasty Femoral Components Without
Molybdenum Alloy for Surgical Implant Applications
Torsion
F 86 Practice for Surface Preparation and Marking of Me-
F 1472 Specification for Wrought Ti-6Al-4V Alloy for Sur-
tallic Surgical Implants
gical Implant Applications
F 90 Specification for Wrought Cobalt-Chromium-
F 1537 Specification for Wrought Cobalt-28 Chromium-6
Molybdenum Alloy for Surgical Implants
This specification is under the jurisdiction of ASTM Committee F04 on
F 1580 Specification for Titanium and Titanium-6 %
Medical and Surgical Materials and Devices and is the direct responsibility of
Aluminum-4 % Vanadium Alloy Powders for Coatings of
Subcommittee F04.22 on Arthroplasty.
Current edition approved Nov. 10, 2000. Published January 2001.
Surgical Implants
Annual Book of ASTM Standards, Vol 13.01.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
F 2068
F 1612 Practice for Cyclic Fatigue Testing of Metallic 3.1.7 modular (Type II) head, n—a femoral head that is not
Stemmed Hip Arthroplasty Femoral Components with integral with the neck and proximal body. It is a convex
Torsion bearing member for articulation with either natural acetabulum
F 1636 Specification for Bores and Cones for Modular or the prosthetic acetabulum. It possesses an integrally ma-
Femoral Heads chined bore for fitting the cone of a modular (Type II) implant.
F 1814 Specification for Evaluating Module Hip and Knee 3.1.8 modular (Type II) implant, n—a femoral hip compo-
Joint Components nent of which the head is not integral with the neck and
F 1854 Test Method for Stereological Evaluation of Porous proximal body of the implant. The modular implant is intended
Coatings on Medical Implants for insertion within the femoral medullary canal. It possesses a
F 1978 Test Method for Measuring Abrasion Resistance of cone that provides a stable connection for the modular (Type
Metallic Thermal Spray Coatings by Using the Tabery II) head.
Abraser 3.1.9 mono-block (Type I) implant, n—a femoral hip com-
2.2 ISO Documents: ponent in which the head is integral with the neck and proximal
ISO 5832-1:1997 Implants for Surgery—Metallic body of the implant.
Materials—Part 1: Wrought Stainless Steel 3.1.10 neck, n—the portion of the femoral prosthesis con-
ISO 5832-3:1996 Implants for Surgery—Metallic necting the proximal body and the prosthetic femoral head. The
Materials—Part 3: Wrought Titanium 6-Aluminum neck is integral with the proximal body, and is either perma-
4-Vanadium Alloy nently attached to the head (Type I devices) or to a cone
ISO 5832-4:1996 Implants for Surgery—Metallic designed to accept a modular head (Type II devices).
Materials—Part 4: Cobalt-Chromium-Molybdenum Cast- 3.1.11 porous surface, n—an outermost layer(s) of all or
ing Alloy part of the femoral implant characterized by interconnecting
ISO 5832-9:1992 Implants for Surgery—Metallic subsurface pores, generally with the volume porosity between
Materials—Part 9: Wrought High Nitrogen Stainless 30 and 70 %, average pore size between 50 and 1000 μm, and
Steel a thickness between 250 and 1500 μm (in accordance with Test
ISO 7206-2:1996 Implants for Surgery—Partial and Total Method F 1854). This porous layer may be manufactured
Hip Joint Prostheses—Part 2: Articulating Surfaces Made directly into the metallic implant by casting or by various
of Metallic, Ceramic and Plastics materials electro/chemical/thermal/mechanical means, or applied as a
ISO 7206-4:1989 Implants for Surgery—Partial and Total coating of particles, beads, or mesh by processes such as
Hip Joint Prostheses—Part 4: Determination of Endurance sintering or plasma spray.
Properties of Stemmed Femoral Components with Appli- 3.1.12 proximal body, n—region of the implant which
cation of Torsion extends distally from the trochanteric region to the diaphyseal
ISO 7206-8:1995 Implants for Surgery—Partial and Total region of the femur. This portion of the implant may be in
Hip Joint Prostheses—Part 8: Endurance Performance of direct apposition with bone or may be fixed in the femoral
Stemmed Femoral Components with Application of Tor- medullary canal using bone cement.
sion 3.1.13 total hip arthroplasty, n—replacement of the natural
femoral head with a prosthetic femoral head held in place by an
3. Terminology
implant extending into the shaft of the femur and replacement
3.1 Definitions of Terms Specific to This Standard: of the natural acetabulum with a prosthetic acetabulum. The
prosthetic femoral head articulates with the bearing surface of
3.1.1 bore, n—an internal cavity, in the form of a truncated
the prosthetic acetabulum.
right cone, used to engage with the cone of a femoral neck.
3.1.2 collar, n—flange at the junction of the neck and
4. Classification of Implant Type
proximal body.
4.1 Femoral prostheses falling within the scope of this
3.1.3 cone, n—the truncated conic geometry on a femoral
specification are of four types as defined as follows. There are
hip prosthesis used to engage with the bore of a femoral head.
not distinguishing features (for example, collars or lack
3.1.4 distal stem, n—region of the implant that extends
thereof, fenestrations, and so forth) that would exempt any
distally from the proximal body. This part of the implant is
device from any requirement of this specification.
intended for insertion within the femoral medullary canal. The
4.1.1 Type IA—Single-piece (mono-block), metallic femo-
distal stem may be in direct apposition with bone or may be
ral total hip or hemi-arthroplasty hip prosthesis with an integral
fixed in the femoral medullary canal using bone cement.
stem, neck and head. The stem is designed such that the center
3.1.5 head, n—convex spherical bearing member for articu-
of the head, the axis of the neck, and proximal body, and the
lation with the natural acetabulum or prosthetic acetabulum.
distal stem all lie in the same medial/lateral plane.
3.1.6 hemi-arthroplasty, n—replacement of the natural
4.1.2 Type IB—Single-piece (mono-block), metallic, femo-
femoral head with a prosthetic femoral head held in place by an
ral total hip or hemi-arthroplasty his prostheses with an integral
implant extending into the shaft of the femur. The natural
stem, neck, and head. The stem is designed such that the center
acetabulum is not altered.
of the head, the axis of the neck, the proximal body, and the
distal stem dot not lie in the same medial/lateral plane. This
3 would include anteverted necks, proximally curved stems,
Available from American National Standards Institute, 11 W. 42nd St., 13th
Floor, New York, NY 10036. distally bowed stems and so forth.
F 2068
NOTE 1—Consult the rationale in Appendix X2 for comments regarding
4.1.3 Type IIA—Modular metallic femoral hip prostheses
the application of 6.1.
that could include a modular (Type II) head or other modular
6.1.1 Fatigue performance of the femoral hip components
components, or both. Such “modular” designs allow for more
flexible inventory management and provide a means for may be characterized by testing in accordance with ISO
7206-4:1989, Practice F 1612, or Practice F 1440. Representa-
adjusting prosthesis neck length and, therefore, leg length at
surgery. The stem is designed such that the center of the head, tive samples shall be able to withstand cyclic loading with a
minimum load of 300 N and a maximum load of 2.3 kN in
the axis of the neck, the proximal body, and the distal stem all
lie in the same medial/lateral plane. accordance with ISO 7206-8:1995 when tested in accordance
with ISO 7206-4:1989 or Practice F 1612, or cyclic loading
4.1.4 Type IIB—Modular metallic femoral hip prosthesis
with a minimum load of 300 N and a maximum load of 3.3 kN
that could include a modular (Type II) head or other modular
when tested in accordance with Practice F 1440. For ASTM
components, or both. Such “modular” designs allow for more
test methods, use an unsupported implant length of 50 mm in
flexible inventory management and provide a means for
accordance with the ASTM definition. The representative test
adjusting prosthesis neck length and, therefore, leg length at
samples should be selected from the standard (average patient)
surgery. The stem is designed such that the center of the head,
size range and which presents the worse case stress conditions
the axis of the neck, the proximal body, and the distal stem do
for the design series. To meet the worse case stress recommen-
not lie in the same medial/lateral plane. This would include
dation, implants should be tested with the worst-case offset
anteverted necks, proximally curved stems, distally bowed
head.
stems, and so forth.
6.1.2 Alternatively, the demonstrated fatigue strength of the
implant size with the highest stresses, when tested with the
5. Materials
worst-case offset head and in accordance with ISO 7206-
5.1 All devices conforming to this specification shall be
4:1989, Practice F 1612, or Practice F 1440, shall be equivalent
fabricated form materials with adequate mechanical strength
to or exceed the demonstrated fatigue strength of a comparable,
and durability, corrosion resistance, and biocompatibility.
clinically successful femoral implant design.
Some examples of materials from which femoral hip prosthe-
ses have been successfully fabricated include Specifications
NOTE 2—While ISO 7206-4:1989 specifies testing in a saline environ-
ment, some researches test in saline and some researchers test in ambient
F 67, F 75, F 90, F 136, F 138, F 562, F 563, F 620, F 745,
laboratory air. Consideration should always be given to corrosion effects
F 799, F 1108, F 1472, F 1537 and F 1580 and ISO Standards
on fatigue and fretting behavior in establishing a test protocol. Materials
5832/1:1997/3:1996/4:1996/9:1992.
which are suspected to environmental sensitivity or which the sensitivity
5.1.1 Mechanical Strength—Not all of the materials listed
level is not know, should be tested in a simulated physiological environ-
in 5.1 possess sufficient mechanical strength for critical highly
ment as recommended in ISO 7602-4:1989 and suggested in Practices
stressed components. Conformance of a selected material to its
F 1440 and F 1612.
standard and successful clinical usage of the material in a
6.2 Coating Integrity Metal Coating (for example, plasma
previous implant design are not sufficient to ensure the strength
spray, porous, and fiber metal)— The porous surface morphol-
of an implant. Manufacturing processes and implant design can
ogy shall be capable of accepting tissue (soft or hard) ingrowth
strongly influence material properties. Therefore, regardless of
to accomplish firm fixation of the device. The porosity may be
the material selected, the femoral hip implant must meet the
uniform, or may be graded from surface to substrate in a
performance requirements of Section 6.
manner to maximize both the interfacial strength and ingrowth
5.1.2 Corrosion Resistance—Materials with limited or not
potential.
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