| ASTM F897-02 (Reapproved 2013) Standard Test Method for Measuring Fretting Corrosion of Osteosynthesis Plates and Screws |
| Recognition Date | 2013-08-06 |
| Recognition List | 031 |
| Recognition Number | 11-215 |
| Extent | Complete standard |
| Standards Orgs | ASTM ASTM International http://www.astm.org/ |
| STG | Orthopedic |
| FDA Tech | Terry O. Woods FDA/OMPT/CDRH/OSEL/DAM/ 301-796-2503 terry.woods@fda.hhs.gov |
This standard is relevant to medical devices and is recognized on its scientific and technical merit and/or because it supports existing regulatory policies.
1.1 This test method provides a screening test for determining the amount of metal loss from plates and screws used for osteosynthesis (internal fixation of broken bones) due to fretting corrosion in the contact area between the screw head and the plate hole countersink area. The implants are used in the form they would be used clinically. The machine described generates a relative motion between plates and screws which simulates one type of motion pattern that can occur when these devices are used clinically.
1.2 Since the environmental and stress conditions used in this test method may not be identical to those experienced by bone plates in the human body, this test method may produce fretting corrosion rates that are lower or higher than those experienced in practice. The recommended axial load of 400 N was selected as being in a range where the amount of fretting corrosion is not sensitive to small changes in axial load (1).2 The combination of the recommended load and angular displacement are such that a measurable amount of fretting corrosion of surgical alloys occurs in a comparatively short period of time (7 to 14 days). (Refs 1-3)
1.3 The device is designed so as to facilitate sterilization of the test specimens and test chambers to permit testing with proteinaceous solutions that would become contaminated with microbial growth in nonsterile conditions.
1.4 The specimens used can be standard osteosynthesis implants or can be materials fabricated into the appropriate shapes.
1.5 This test method may be used for testing the fretting corrosion of metal plates and screws of similar or different alloy compositions, or it may be used for testing the fretting corrosion of metal-nonmetal combinations. This test method may also be used for wear or degradation studies of nonmetallic materials. This test method may be used as a screening test to rank the corrosivities of saline or proteinaceous solutions, or to rank metal-to-metal couples for resistance to fretting corrosion, or to study other material combinations.
| Regulation Number | Device Name | Device Class | Product Code |
| §888.3040 | Screw, Fixation, Bone | Class 2 | HWC |
| §888.3030 | Appliance, Fixation, Nail/Blade/Plate Combination, Multiple Component | Class 2 | KTT |
| §888.3030 | Appliance, Fixation, Nail/Blade/Plate Combination, Multiple Component, Metal Composite | Class 2 | LXT |
| §888.3030 | Appliance, Fixation, Nail/Blade/Plate Combination, Single Component | Class 2 | KTW |
| §888.3030 | Appliance, Nail/Blade/Plate Combination, Single Component | Class 2 | KWK |
| §888.3030 | Condylar Plate Fixation Implant | Class 2 | JDP |
| §888.3030 | Device, Fixation, Proximal Femoral, Implant | Class 2 | JDO |
| §888.3030 | Plate, Fixation, Bone | Class 2 | HRS |
| Method applies specifically to osteosynthesis plates and screws indicated by the following procodes. However, the method may be used to analyze susceptibility to fretting corrosion of material combinations in other orthopaedic device applications. | |||
| Guidance Document for Testing Non-Articulating, 'Mechanically Locked,' Modular Implant Components, May 1, 1995 |