Physical properties of autoclaved bone. Torsion test of rabbit diaphyseal bone.

Structural properties of autoclaved diaphyseal bone in the rabbit were investigated by torsional test. Heat propagation into the bone was studied by means of thermocouples. The torsional test included 54 pairs of diaphyseal bones. Autoclaving was performed to the same degree of sterilization, although with variations of time and temperature. Standard autoclaving at 121 degrees C for 20 min was found to cause a moderate decrease (23 per cent) in torsional strength. The decrease was more pronounced (35 per cent) for bones autoclaved at 110 degrees C for 255 min and less (9 per cent) for those autoclaved at 131 degrees C for 2 min. Heat propagation into bone during autoclaving proved to be rapid at both 121 degrees C and 131 degrees C, indicating that complete, uniform sterilization of diaphyseal bone may be performed to an accurate, predetermined degree. Diaphyseal bone subjected to standard autoclaving remains mechanically adequate for skeletal substitution. Reimplantation of autoclaved tumorous bone might provide a simple combined means for tumor devitalization and subsequent reconstruction.