ASTM F2028-05

Standard Test Methods for Dynamic Evaluation of Glenoid Loosening or Disassociation

SIGNIFICANCE AND USE
This test method is intended to investigate the resistance of a glenoid component to loosening. Glenoid loosening is the most common clinical complication in total shoulder arthroplasty (see X1.1). The method assumes that loosening occurs because of edge loading, often called the rocking-horse phenomenon.
This test method can be used both to detect potential problems and to compare design features. Factors affecting loosening performance include articular geometry, flange geometry, materials, fixation design, bone quality, and surgical technique.
SCOPE
1.1 These test methods measure how much a prosthetic glenoid component rocks or pivots following cyclic displacement of the humeral head to opposing glenoid rims (for example, superior-inferior or anterior-posterior). Performance is judged by the tensile displacement opposite each loaded rim after dynamic rocking.
1.2 The same setup can be used to test the locking mechanism of modular glenoid components, for example, for disassociation.
1.3 These test methods cover shoulder replacement designs with monolithic or modular glenoid components for cemented fixation.
1.4 The values stated in SI units are to be regarded as the standard. The values given in parentheses are provided for information purposes only.
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-Jul-2005
• ICS: 11.040.40 - Implants for surgery, prosthetics and orthotics
• Technical Committee: F04 - Medical and Surgical Materials and Devices
• Drafting Committee: F04.22 - Arthroplasty

Relations

• Replaces: ASTM F2028-02 - Standard Test Methods for the Dynamic Evaluation of Glenoid Loosening or Disassociation
• Effective Date: 01-Aug-2005
• Replaced By: ASTM F2028-08 - Standard Test Methods for Dynamic Evaluation of Glenoid Loosening or Disassociation
• Effective Date: 01-Feb-2008
• Referred By: ASTM F1378-18e1 - Standard Specification for Shoulder Prostheses
• Effective Date: 01-Aug-2005

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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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:F2028–05
Standard Test Methods for
Dynamic Evaluation of Glenoid Loosening or
1
Disassociation
This standard is issued under the fixed designation F 2028; 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 3.1.1 glenoid—the prosthetic portion that replaces the gle-
noid fossa of the scapula and articulates with a prosthetic
1.1 These test methods measure how much a prosthetic
replacementofthehumeralhead.Itmayconsistofoneormore
glenoid component rocks or pivots following cyclic displace-
components from one or more materials, for example, either
ment of the humeral head to opposing glenoid rims (for
all-polyethylene or a metal baseplate with a polymeric insert.
example, superior-inferior or anterior-posterior). Performance
3.1.2 humeral head—theprostheticportionthatreplacesthe
is judged by the tensile displacement opposite each loaded rim
proximal humerus or humeral head and articulates with the
after dynamic rocking.
natural glenoid fossa or a prosthetic replacement.
1.2 The same setup can be used to test the locking mecha-
3.1.3 glenoid plane—see Fig. 1. In symmetric glenoids, the
nism of modular glenoid components, for example, for disas-
plane is defined by joining the two articular edges; in planar
sociation.
and asymmetric glenoids, it is defined by the back surface.
1.3 These test methods cover shoulder replacement designs
with monolithic or modular glenoid components for cemented
fixation.
1.4 The values stated in SI units are to be regarded as the
standard. The values given in parentheses are provided for
information purposes only.
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 appro-
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
2. Referenced Documents
2
2.1 ASTM Standards:
FIG. 1 Glenoid Plane and Load Directions
E4 Practices for Force Verification of Testing Machines
F 1378 Specification for Shoulder Prostheses
F 1839 Specification for Rigid Polyurethane Foam for Use
3.1.4 axial load; axial translation—the force and displace-
as a Standard Material for Testing Orthopaedic Devices
3 ment,respectively,perpendiculartotheglenoidplane;theaxial
and Instruments
load simulates the net compressive external and muscle forces
3. Terminology (see Fig. 1).
3.1.5 shear load; shear translation—the force and displace-
3.1 Definitions:
ment, respectively, parallel to the glenoid plane, applied, for
example, in the superior/inferior or anterior/posterior direction
1
These test methods are under the jurisdiction of ASTM Committee F04 on (see Figs. 1 and 2); the shear load simulates the net shear
Medical and Surgical Materials and Devices and are the direct responsibility of
external and active and passive soft tissue forces.
Subcommittee F04.22 on Arthroplasty.
3.1.6 subluxation load—the peak shear load required for
Current edition approved Aug. 1, 2005. Published August 2005. Originally
subluxation,forexample,thepeakresistiveforceattheglenoid
approved in 2000. Last previous edition approved in 2002 as F 2028 – 02.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
articular rim opposing movement of the humeral head.
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
3.1.7 subluxation translation—the distance from the gle-
Standards volume information, refer to the standard’s Document Summary page on
noid origin (see Fig. 2), parallel to the glenoid plane, to the
the ASTM website.
3
Withdrawn. point at which the subluxation load occurs.
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F2028–05
FIG. 2 Glenoid Axes and Origin
3.1.8 superior/inferior (SI), anterior/posterior (AP)—the SI 3.1.9 edge displacements—the translation, perpendicular to
axis is the longest dimension and the AP axis the widest the glenoid plane, of a specific point on the outside edge of the
dimension of the glenoid (see Fig. 2). glenoid, when subjected to loading (see Fig. 3).
GLENOID LOOSENING TEST METHOD
4. Summary of Test Method to the glenoid, then the edge displacements are measured with
the humeral head in three positions: at the glenoid origin, and
4.1 The prosthetic glenoid component is fixed with bone
positioned to 90 % of the subluxation translation (see X1.2), in
cement into a bone substitute using the normal surgical
both directions, as defined in 4.2. (Cyc
...