An in vitro study of thermal necrosis in ultrasonic-assisted drilling of bone

In case of human bone fracture, the best way to better and faster knitting is when a traumatologist fixes the fractured bone ends by drilling and setting the immobilization plates by screws. Heat generation during bone drilling may result in thermal injury due to exposure to elevated temperatures, with potentially devastating effect on the outcome of orthopedic surgery. A recent and promising method for reducing temperature in bone drilling is the use of ultrasonic assistance, where high-frequency and low-amplitude vibrations are added in feed direction during cutting process. In this research, experimental tests are carried out in five cutting speeds and three feed rates. The results demonstrate that ultrasonic-assisted drilling offered lower thrust forces and lower process temperatures as compared to conventional drilling at 1000 r/min. In addition, it is obvious that at 2000 r/min, since the values of temperature rise and thermal injury are independent from the feed rate, this method can be applied in the orthopedic surgery.