Effect of microwave oven induced mild hyperthermia on bone viability and strength

Extracorporeal hyperthermia treatment of bone followed by reimplantation ma y be an option for treating bone tumors. However, intensive heat treatment, such as autoclaving, causes a decline. of mechanical and biologic function s of bone tissue, In the current study, a microwave oven was used for minim al hyperthermic treatment, and it was found that complete eradication of al l viable cells in rat bone could be achieved with minimal reduction in mech anical function, When the cells were evaluated histologically by special la ctate dehydrogenase activity staining, complete bone cell death occurred af ter 60 seconds of heating in an empty Petri dish and after 30 seconds when heated in a Petri dish containing normal saline. Mechanical stiffness and s trength of the bones, tested in three-point bending, showed no decrease aft er this heating, Microwave oven induced hyperthermia eradication of viable cells without significant damage to the mechanical properties may have clin ical relevance in limb salvage tumor surgery.