A proposed new ASTM International standard will cover fatigue testing of metallic tibial trays, which are components used in partial knee joint replacement. ASTM WK45235, Practice for Cyclic Fatigue Testing of Metal Tibial Tray Components of Unicondylar Knee Joint Replacements, is being developed by Subcommittee F04.22 on Arthroplasty, part of ASTM International Committee F04 on Medical and Surgical Materials and Devices.

According to Gokce Yildirim, research engineer, Stryker MAKO, and a member of F04, the test in ASTM WK45235 is for materials used in transplants for a middle-aged population (40 and up) who have arthritis forming on the medial side of their knees, but who have healthy cruciate ligaments. “Solving the arthritis pain issue is known to restore normal knee function and give patients more mobility for their daily lives,” says Yildirim.

Yildirim notes that the testing described in ASTM WK45235 mirrors fatigue testing that covers total knee replacement tibial trays. Once the standard has been approved, it will be used by medical device companies as well as testing laboratories. The purpose of the test will be to indicate that the tibial metal component will not fail over its expected lifetime.