Identification of effective elastic modulus using modal analysis; application to canine cancellous bone

Area of Science:

• Biomechanics
• Materials Science
• Orthopedics

Background:

• Mechanical properties of cancellous bone are crucial for understanding aging pathologies and oncology.
• Characterizing fragile bone tissue is challenging, with current methods including quasi-static compression, ultrasound, and indentation.
• Existing techniques face limitations in assessing the mechanical integrity of delicate and limited bone samples.

Purpose of the Study:

• To investigate modal analysis of flexure beams as a complementary method for determining Young's modulus in bone.
• To validate a novel sampling methodology for dynamic linear response analysis.
• To assess the feasibility of using natural frequencies and mode shapes for elastic modulus determination.

Main Methods:

• Modal analysis of beam-like specimens under clamped-free boundary conditions.
• Validation using a synthetic bone model.
• Water-jet cutting to prepare fourteen small specimens from canine distal femurs.
• X-ray microtomography for microarchitecture assessment and confirmation of homogeneity and isotropy.

Main Results:

• Young's modulus values ranged from 210 MPa to 280 MPa, varying by specimen collection site.
• The methodology demonstrated rapid and reproducible experimental testing.
• Preliminary results showed good agreement with existing literature data for bone mechanical properties.

Conclusions:

• Beam modal analysis presents a viable and complementary approach for evaluating the mechanical properties of fragile and scarce biological tissues.
• This technique offers a non-destructive and efficient method for bone characterization.
• Further research can explore its application in clinical settings for diagnosing bone conditions.