 The embolisation of fat and bone marrow during long bone instrumentation is a well-known complication of major joint replacement surgery. Clinically significant venous thromboembolic disease, cardiopulmonary dysfunction,cerebral emboli, and death have all been described. Because the intravasation of medullary contents is caused by increased pressure during canal instrumentation, the use of the Synthes RIA Reamer-Irrigator-Aspirator, a negative pressure-irrigated high-speed reamer, may result in a lower incidence of embolism. 