3D Full-field Bone Biomechanics Study: Effects of Diseases and Treatments
Open Access
- Author:
- Zhou, Yuxiao
- Graduate Program:
- Mechanical Engineering
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- December 16, 2020
- Committee Members:
- Jing Du, Dissertation Advisor/Co-Advisor
Jing Du, Committee Chair/Co-Chair
Mary I Frecker, Committee Member
Reuben H Kraft, Committee Member
April D Armstrong, Outside Member
Daniel Connell Haworth, Program Head/Chair - Keywords:
- Biomechanics
Atomic Force Microscopy
Digital Volume Correlation
Dental implant
Glenohumeral joint
Rheumatoid arthritis - Abstract:
- Bone is a complex anisotropic hierarchical composite that consists of inorganic and organic components. Bone is also a living material that adapts to mechanical stimulations through continuous modeling and remodeling activities. The morphology and mechanical properties of bone change as a result of diseases and treatment. This study presents the results of a combined experimental and theoretical study of mechanical behaviors and microstructures of bone in human and animals as affected by several diseases and treatments. The applications areas include osteoarthritis and total shoulder arthroplasty; tooth loss and dental implant treatment; and autoimmune arthritis and gingival mesenchymal stem cells (GMSC) treatment. In each of these areas, this work utilized mechanical testing coupled micro X-ray computed tomography (micro-CT) that enable concurrent non-invasive characterization of 3D fullfield bone microstructures and bone mechanical properties. Also, atomic force microscopy (AFM) was used to map the surface morphology and elastic properties of bone from sub-millimeter to sub-micron scale. The experimental results are integrated with analytical models to provide mechanical insights for the potential improvement of these treatments. The study of osteoarthritis and shoulder replacement surgery explored the deformation and strain range inside glenoid bone, and analytical model was proposed to explain the experimental observations. Mechanical testing coupled with micro-CT was performed to apply various physiologically realistic loads on a native and implanted glenoid. Digital volume correlation was used to compute the 3D full-field deformation and strain inside the glenoid. The measured strain distributions were in good agreement with the analytical solutions of beam bending models, especially for anteriorly and posteriorly eccentric loadings. The effective moduli of the overall native and implanted glenoid were also being discussed. This study provides a feasible and powerful method for the study of 3D full-field biomechanics in native and implanted glenoids. Subsequently, the biomechanics of bone-tooth and bone-implant contacts was being investigated by performing mechanical testing coupled with micro-CT. Strain in bone increased when a tooth was replaced by dental implant. Furthermore, strain concentration was observed in peri-implant bone, as well as in the buccal bone plate, which is in agreement with clinically-observed bone resorption area after implant placement. Implant stability measurements (resonance frequency analysis and installation torque analysis) and bone-implant contact ratio are also measured, and their relationships with strain in peri-implant bone and buccal bone plate are being investigated. The results of this study revealed contact as well as 3D full field strain in bone-tooth and bone implant constructs, as well as their several morphological influential factors. Also, bone erosion caused by collagen induced arthritis (CIA) and suppression of the development of established CIA in mice treated with human gingiva-derived mesenchymal stem cells (GMSCs) were examined by assessing the microstructure and mechanical behaviors of mouse tibia bone. The study presents bone morphology and mineral density of mouse tibiae using micro-CT images, stiffness of proximal tibiae under compression test, and deformation and strain localized inside proximal tibia using digital volume correlation of micro-CT images. GMSCs were found to attenuate bone erosion in epiphyseal and metaphyseal trabecular bone, and resulted in improved loading bearing function of tibia. The findings in this study concluded that GMSCs provide a promising potential treatment of autoimmune arthritis. Bone is a composite material consisting of organic and inorganic components that organized into hierarchical structures to provide load-bearing functions. This study presents the results of PeakForce Tapping atomic force microscopy (AFM) scans on cut and polished bovine cortical bone specimens that were submerged in water. The elastic modulus map and surface morphology were obtained for various bone hierarchical structures from cement line, thick and thin osteon lamella at submillimeter-scale, to mineralized collagen fibril and extrafibrillar matrix at submicron-scales. The variations in the elastic modulus suggest different degrees of mineralization or different fibril orientations, and the histograms of elastic modulus indicate the dominating compositions or dominating fibril orientations.