MechE PhD Prospectus Defense: Benjamin Olowu

TITLE: DEVELOPMENT OF ASSESSMENT METHODS FOR INVESTIGATING THE MECHANICAL BEHAVIOR OF BONE

ABSTRACT: Bone tissues are constantly subjected to various loads, making it essential to understand their mechanical behavior. The limitations of current clinical assessment methods, such as relying solely on bone mineral density (BMD) measurement to predict bone's biomechanical behavior, have led to increased interest in computational modeling approaches. Unlike BMD, which focuses only on bone quantity, computational models account for bone geometry, material properties, and microarchitecture, offering a more comprehensive and personalized prediction of mechanical behavior. However, these models require validation and comprehensive comparative studies prior to broad clinical application. In addition, the prevalence of bone injuries has pushed the growth of bone tissue engineering, particularly towards the use of additively manufactured bioceramic scaffolds to support the repair of large bone defects. To assess the performance of these scaffolds toward healing, much of the existing research has focused on the biological assessment of healing, neglecting a comprehensive understanding of the mechanical integrity of the regenerated bone. This knowledge gap exists in part due to a methodological gap; current mechanical testing methods are limited in their ability to directly and precisely assess the healing region. Therefore, the primary goal of my research is to advance methods for evaluating and predicting bone mechanical behavior in the context of injury and healing. Aim 1 will investigate, compare, and assess patient-specific finite element models (FEM) derived from computer tomography(CT) and magnetic resonance imaging (MRI) data to simulate fracture in the proximal femur during a sideways fall—a leading cause of hip fractures. Aim 2 will leverage additive manufacturing to develop a mechanical testing fixture tailored to the intricate geometry of bone, addressing the need for a reliable way to evaluate the mechanical properties of healing tissues ex vivo. Aim 3 will examine how scaffold architecture affects the strength, stiffness, and toughness of bone as it regenerates, using the testing setup developed in Aim 2. Collectively, this research will provide insight into the predictive extent of computational models, improve biomechanical testing methods, and elucidate the influence of scaffold architecture on the strength of new tissues formed during healing in a murine model.

COMMITTEE: ADVISOR/CHAIR Professor Elise Morgan, ME/MSE/BME; Professor Katherine Yanhang Zhang, ME/BME/MSE; Professor Douglas Holmes, ME/MSE