Purdue University Graduate School
Browse

File(s) under embargo

6

month(s)

7

day(s)

until file(s) become available

INTRINSIC STRENGTH AND TOUGHNESS OF HUMAN CORTICAL BONE

thesis
posted on 2024-04-19, 13:55 authored by Mary Catherine ArnhartMary Catherine Arnhart

Investigating the deformation and failure of human cortical bone under altered hydration contributes to the understanding of bone fracture. Further, studying the impact of hydration on bone deformation can lead to developing fracture prevention strategies that will enhance the lives of the aging population. In addition, characterization of cortical bone water modulation effects on biomechanical behavior helps us understand how bone dynamically changes due to aging, health conditions, and therapeutic interventions.

The concepts in this thesis are demonstrated on bone specimens of a 75-year-old male human subject. To investigate the potential role of water in bone as modulated by selective estrogen receptor modulators, we used magnetic resonance imaging to characterize bound water in human samples. The behavior of human cortical bone under mechanical loading protocols was tested to analyze the bone failure surface. Bone microstructure, microdamage, and fractures were observed from progressive bending experiments. Earlier evidence suggests that treating human cortical bone with Raloxifene (RAL) toughens bone but does not affect strength.

Questions remain about how RAL treatment affects bone biomechanics with the consideration of size effects. In this research, experiments were conducted on samples mimicking the thickness of cortical bone. Smaller thickness samples investigated in prior work were also considered, and intrinsic strength and tissue damage were introduced. Additionally, ultra-short echo-time magnetic resonance images were employed to observe 3D spatial information of bound and free water in the bone.

This research seeks to combine methods in bone biology and the mechanics of materials to solve problems of bone fragility. Linear strength concepts do not distinguish between treatments. However, treatment effects are detected with a nonlinear approach. Furthermore, this study provides valuable insights into quantifying bound water content within in-vitro specimen samples. These findings pave the way for further research into continued advancements addressing skeletal health challenges.

Funding

NSF Award 1952993

History

Degree Type

  • Master of Science in Mechanical Engineering

Department

  • Mechanical Engineering

Campus location

  • West Lafayette

Advisor/Supervisor/Committee Chair

Thomas Siegmund

Additional Committee Member 2

John Howarter

Additional Committee Member 3

Laura J. Pyrak-Nolte

Usage metrics

    Categories

    Licence

    Exports

    RefWorks
    BibTeX
    Ref. manager
    Endnote
    DataCite
    NLM
    DC