A Probabilistic Fracture Assessment of Vertebral Cortical Bone

Cortical bone is a material with a porous structure. The presence of pores creates local stress concentrations and the likelihood of premature failure. Assuming that pores are present in all bone, vertebral endplates, for example, can subside. Subsidence has taken place at rates as high as 77 percent. A computational probabilistic assessment of the pore size distribution and their contribution to the fracture toughness has been presented in this paper. A Monte Carlo simulation was used to develop and assign random pores. Also the model compared crack sizes to the thickness of the cortical bone present as a limiting case. The a/W (crack length to specimen depth) ratio was a controlling parameter for the fracture case in support of ASTM 399 and published models were used in this research with probabilistic distribution of pores. The probabilistic analyses presented a conservative solution and may be applicable in medical device design.