1.1 This practice provides an evaluation method for the susceptibility of modular head or neck systems or both on femoral stems used in total hip arthroplasty to fretting corrosion under cyclic fatigue forces in simulated corrosive environments. This is a standard in development it should not be applied to existing devices. 1.2 This practice describes methods to accelerate the fretting corrosion effects and evaluate the resistance of new modular head or neck systems or both to fretting/corrosion before clinical use. This practice may not be suitable for other modular taper systems. 1.3 The values stated in SI units are to be regarded as the standard. 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 determine the applicability of regulatory limitations prior to use.
This practice can be used to rank the effects of head and cone materials, design variables, manufacturing, and other conditions on the resistance to fretting corrosion under cyclic forces in a simulated human body environment. These test methods shall use the modular femoral components that meet the full requirements of the modular components of actual femoral prostheses. The materials and processing shall be the same as the final finished products with the exception of sterilization. The test may reveal features of materials, material combinations, designs, and manufacturing processes that work to inhibit the occurrence of crevice corrosion. In the fatigue test methods, it is recognized that actual loading in vivo is quite varied and that no one set of experimental conditions can encompass all possible variations. Thus, the test methods included here represent a simplified model for the purposes of comparisons between designs and materials. The environment is representative of the saline environment for the femoral prosthesis in the human body with the exception that the reactivity of the environment is accelerated by increasing the temperature higher than the normal temperature of the human body and using acid to decrease the pH of the environment to accelerate the decrease in pH than can occur in crevices with metallic surfaces.
Keywordsfatigue; fretting; fretting corrosion; hip; modular; taper; adapter; sleeve; crevicecorrosion; modular heads; modular tapers and bores; potentiostatic current monitoring
The title and scope are in draft form and are under development within this ASTM Committee.Back to Top
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