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An 8870 fatigue testing system with a custom fixture for an
angled orthopaedic fixation device. These tests are run for thousands of cycles
to simulate loading of the device in vivo.
The Challenge
Angled orthopedic fixation devices are used to treat fractures in the
metaphyseal areas of long bones. Loading creates a compression bending load at
the angled portion, which must be evaluated for strength and stiffness by
researchers when comparing materials and designs, and also by the surgeon to
predict performance. Fatigue life over a specific time or loading range must
also be determined. For these reasons, the test fixture must simulate
compressive loads experienced by the angled portion of the plate as a result of
body weight.
Our Solution
Testing is based on ASTM standard F 384, 'Standard Specifications and Test
Methods for Metallic Angled Orthopedic Fracture Fixation Devices'. For static
testing, a ramped compression load is applied until the fixation device
plastically deforms or a set deflection is reached. The objective is to
determine the static bending stiffness of the plate. Four-point bending and
fatigue testing, using an 8870 fatigue testing system, is also necessary to
accurately evaluate the fixation device. The fixture is designed to work with
or without a saline bath and can be adapted to suit a variety of specimen sizes
and geometries.
Other Medical Devices
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