Micro-computed tomography studies of biomaterials and bone

Abstract

This thesis is presented in two parts; the first part is a study of the structure and properties of bioceramic scaffolds used for orthopaedic tissue engineering and how these factors may influence bone regeneration. The second part of this thesis is a study of the effects of bone microarchitecture on the mechanical properties of the human proximal femur. Strategies for orthopaedic tissue engineering involve the use of a porous ceramic or polymer scaffold to serve as a template for bone regeneration. However, the design and engineering of these scaffolds is ad hoc. The effect of porosity, pore size, shape, interconnectivity, transport and mechanical properties on bone growth is not well understood and remains a significant challenge to successful bone regeneration. We use 3D micro-CT imaging and analysis approach to generate measures of local and non-local pore size, pore interconnectivity, transport and mechanical properties directly from images of explanted hydroxyapatite constructs from a sheep model. We develop a method to accurately phase separate pore, bone and scaffold phases using a three-phase segmentation algorithm. We also observe a strong correlation with bone ingrowth and measures of non-local pore size which account for pore accessibility. This study demonstrates the utility of micro-CT and quantitative 3D analysis to analyse tissue engineered implants. <…>