Mechanically Active Bone Fixation Device: Design and Characterization

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Date

2021

Authors

Fear, Karly

Journal Title

Journal ISSN

Volume Title

Publisher

University of Oregon

Abstract

Mechanical stimulus in the form of exercise is known to improve bone formation during fracture healing. At a scale orders of magnitude smaller than this functional loading, mechanical stimulus delivered at high frequency (~30 Hz) can also enhance bone regeneration. External delivery of mechanical stimulus is used in many of the studies that demonstrate the positive effects of this low magnitude, high frequency (LMHF) stimulus, but these modes of delivery are challenging to translate into clinical settings. In this study, we fabricated and tested an internal delivery system comprised of a bone fixation device embedded with a magnetoelastic actuator which will change physical dimension in response to an applied magnetic field. Load transferred from the mechanically active device to a rodent femoral fracture provides local LMHF stimulus. The bone fixation device was characterized by off-axis compressive and torsional stiffness tests and accelerated fatigue tests. Iterative design produced a fixation device with the required stiffness parameters for in vivo validation.

Description

1 page.

Keywords

nonunion fracture, regenerative medicine, mechanical stimulation, magnetoelastic, orthopedic rehabilitation

Citation