Ultrasonic energy and surgically produced defects in bone.

A study was made of the effect of ultrasonic energy on the healing of defects created surgically in the femora of sixty-seven dogs. The ultrasonic energy was applied to anaesthetized dogs with a power ranging from five to twenty-five watts in various groups of animals. Stimulation of the healing of these defects its bone was not seen. Instead, a delay in healing associated with medullary fibrosis and necrosis of bone was noted. This agrees in part at least with work reported by others. In view of recently reported studies claiming stimulation of the healing of fractures following use of a different technique of ultrasonic application and smaller doses, the need for further investigation along these lines is obvious. It is probable that more frequent and less concentrated exposures, with use of a technique and dosage comparable to those used clinically, applied to non-anaesthetized animals would provide the answer to this question. Now that the effects of more intensive amounts of energy have been studied, this would appear to be the next step.