Heat generation during cement removal in revision total hip replacement - a comparison of three methods

High speed cutting and ultrasound devices for cement extraction from the femoral cavity in hip revision procedures are frequently used. Such devices generate heat at the cutting interface which may damage osteocytes. One ultrasound device, a manual high-speed cutter and a robot-based high-speed cutter were tested in human cadaveric bone at body temperature. Temperature probes were placed at the cement-bone interface, and data collected from 12 sensors with a digital data-logger during cement removal from the femoral cavity. Peak temperatures from each sensor were recorded and compared by Kruskal-Wallis-H-Test for global effect and Mann-Whitney-U-Test for multiple comparisons. All devices generated mean temperature peaks of over 50 degrees C which is above levels considered safe. A peak temperature of 164 degrees C was reached by the ultrasound system. Significant differences between the three devices exist, with the ultrasound generating the highest median peak temperatures of 107 degrees C. The lowest median peak temperature of 65 degrees C was generated by the high-speed cutting system.Major improvements of the irrigation and cooling systems of the devices seem to be necessary.