The effect of autoclaving on the mechanical properties of bank bovine bone.

Xenologous bone grafts are frequently used in modern orthopaedic surgery. There is a risk of infection associated with the transmission of diseases among different species for these types of grafts. As for bovine bone grafts in recent times attention has been paid to the diffusion in various countries of the European Economic Community of "bovine spongiform encephalopathy"; this pertains to the same group of encephalopathies as Creutzfeldt-Jakob disease which strikes humans and has a lethal outcome. Thus, in the absence of clinical evidence, there is a potential source of risk of infection associated with specimens of bovine origin in relation to which a document of the European community suggests proceeding by sterilization by autoclaving at 132 degrees C. for at least 1 hour. It is the purpose of this study to verify the effect of this treatment on the mechanical properties of bone graft. The results show how this procedure reduces the graft's resistance to compression by approximately 70%. Thus, it is not acceptable for all bone grafts for which good mechanical resistance is required. In cases such as these, bovine bone grafts may be used only when the immunity of the farm of origin has been certified; then sterilization may be conducted using methods that are less destructive for the mechanical integrity of the bone tissue.