Effects of mechanical stress/strain and estrogen on cancellous bone structure predicted by fuzzy decision

A theoretical model was developed on the basis of fuzzy decision to predict cancellous bone structure following changes in mechanical stress/strain an d estrogen. The model nas validated experimentally by simulation of the nor mal structure of a rat distal femur, and further used to predict the struct ural alterations following ovarian hormone deficiency. The results show tha t net bone resorption after ovariectomy occurs in the metaphysis at locatio ns where trabecula were subjected to the lowest mechanical stress/strain, T hese findings, consistent with experimental results, suggest that estrogen deficiency increase the mechanostat set point at which bone tells perceive mechanical stress/strain. Additionally, the results show that changes in bo ne architecture which are due to alterations in bone remodeling can be simu lated by fuzzy decision without precise mathematical description, and multi ple factors can also be readily incorporated into the model.