Significance and Use
A1.4.1 This test method describes a static bending test to determine the bending stiffness and bending strength of the central and uniform portions of an IMFD.
A1.4.2 This test method may not be appropriate for all types of implant applications (that is, in proximal or distal extremity of an IMFD where screw holes exist). The user is cautioned to consider the appropriateness of the method in view of the devices being tested and their potential applications.
1.1 This specification is intended to provide a characterization of the design and mechanical function of intramedullary fixation devices (IMFDs), specify labeling and material requirements, provide test methods for characterization of IMFD mechanical properties, and identify needs for further development of test methods and performance criteria. The ultimate goal is to develop a standard which defines performance criteria and methods for measurement of performance-related mechanical characteristics of IMFDs and their fixation to bone. It is not the intention of this specification to define levels of performance or case-specific clinical performance of these devices, as insufficient knowledge to predict the consequences of the use of any of these devices in individual patients for specific activities of daily living is available. It is not the intention of this specification to describe or specify specific designs for IMFDs.
1.2 This specification describes IMFDs for surgical fixation of the skeletal system. It provides basic IMFD geometrical definitions, dimensions, classification, and terminology; labeling and material specifications; performance definitions; test methods and characteristics determined to be important to in-vivo performance of the device.
1.3 Multiple test methods are included in this standard. However, the user is not necessarily obligated to test using all of the described methods. Instead, the user should only select, with justification, test methods that are appropriate for a particular device design. This may be only a subset of the herein described test methods.
1.4 This specification includes four standard test methods:
1.4.1 Static Four-Point Bend Test Method— and
1.4.2 Static Torsion Test Method— .
1.4.3 Bending Fatigue Test Method— .
1.4.4 Test Method for Bending Fatigue of IMFD Locking Screws— .
1.5 A rationale is given in .
1.6 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.