Significance and Use
A2.5.1 The test method establishes a uniform four-point bending fatigue test to characterize and compare the fatigue performance of different bone plate designs. This test method may be used to determine a bone plate's fatigue life at either a specific or over a range of maximum bending moment conditions. Additionally, the test method may be alternatively used to estimate a bone plate's fatigue strength for a specified number of fatigue cycles.
A2.5.2 The test method utilizes a simplified bone plate load model that may not be exactly representative of the in-situ loading configuration. The user should note that the test results generated by this test method can not be used to directly predict the in vivo performance of the bone plate being tested. The data generated from this test method can be used to conduct relative comparisons of different bone plate designs.
A2.5.3 This test method may not be appropriate for all types of implant applications. The user is cautioned to consider the appropriateness of the method in view of the devices being tested and their potential application.
A2.5.4 This test method assumes that the bone plate is manufactured from a material that exhibits linear-elastic material behavior. Therefore, the method is not applicable for testing bone plates made from materials that exhibit non-linear elastic behavior.
A2.5.5 This test method is restricted to the testing of bone plates within the materials' linear-elastic range. Therefore, the test method is not applicable for testing bone plates under conditions that would approach or exceed the bending strength of the bone plate being tested.
Abstract
This specification and test method establishes the consistent methods for classifying, and defining the geometric and performance characteristics of five types (cloverleaf, cobra head, reconstruction, straight, and tubular) of metallic bone plates used in the surgical internal fixation of the skeletal system. Also presented here are catalogs of standard specifications for material, labeling, and handling requirements, and standard test methods for measuring performance related mechanical (single cycle bend and bend fatigue) characteristics determined to be important to the in vivo performance of bone plates. This neither defines the levels of performance or case-specific clinical performance for bone plates, nor describes specific designs for bone plates.
Scope
1.1 This specification and test method is intended to provide a comprehensive reference for bone plates used in the surgical internal fixation of the skeletal system. The standard establishes consistent methods to classify, define the geometric characteristics, and performance characteristics of bone plates. The standard also presents a catalog of standard specifications that specify material; labeling and handling requirements; and standard test methods for measuring performance related mechanical characteristics determined to be important to the in vivo performance of bone plates.
1.2 It is not the intention of the standard to define levels of performance or case-specific clinical performance for bone plates, as insufficient knowledge is available to predict the consequences or their use in individual patients for specific activities of daily living. Futhermore, it is not the intention of the standard to describe or specify specific designs for bone plates used in the surgical internal fixation of the skeletal system.
1.3 This document may not be appropriate for all types of bone plates. The user is cautioned to consider the appropriateness of the standard in view of a particular bone plate and its potential application.
1.4 This document includes the following test methods used in determining the following bone plate mechanical performance characteristics.
1.4.1 Standard Test Method for Single Cycle Bend Testing of Metallic Bone Plates—Annex A1.
1.4.2 Standard Test Method for Determining the Bending Fatigue Properties Of Metallic Bone Plates—Annex A2.
1.5 The values stated in SI units are to be regarded as standard. The values given in parentheses are mathematical conversions to inch-pound units that are provided for information only and are not considered 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. A2.1.1 This test method describes methods for bending fatigue testing in order to determine intrinsic, metallic bone plate structural properties. The test method may be used to determine the fatigue life at a specific or over a range of maximum bending moment levels, or to estimate the fatigue strength for a specified number of fatigue cycles of a bone plate. A2.1.2 This test method is intended to provide a means to mechanically characterize different bone plate designs. It is not the intention of this standard to define bone plate performance levels since insufficient knowledge is available to predict the consequences of the use of a particular bone plate design. A2.1.3 Units—The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. A2.1.4 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 to determine the applicability of regulatory limitations prior to use. Note A2.1—There is currently no ISO standard that is similar or equivalent to this test method.
