Objective Quantification of Porous Structure in Orthopaedic Biomaterial Implants Using Micro Computed Tomography

Porous calcium phosphate ceramics have been widely investigated in orthopaedic surgery as bone extensor. Attention has been given to manufacturing of a porous bioceramic that mimics the trabecular bone structure for proper bone regeneration and integration. Although different methods have been applied to manufacture the porous structure, it was unable to visualize the pores and their interconnections within the ceramic and had objective measurement of the calcium phosphate ceramics. With the advance of biomedical imaging through micro-computed tomography (microCT), the study attempted to quantify the pore structure of different calcium phosphate ceramics. Three kinds of bioceramic blocks, namely BSC, ChronOS, and THA, were synthesized by three methods and tested in the study. Six blocks of each bioceramic were evaluated by conventional water immersion method and microCT. The pore size and connectivity of the pores were evaluated with standardized protocols. The three-dimensional analysis of the pores and their distribution by microCT was presented. The ChronOS had more functional pores (200-400μm in diameter) than the BSC and THA did (p<0.05). Providing objective information on the functional pores, the microCT evaluation serves as a good standard for specification of the bioceramic-related implants.