Optimization of bone drilling process based on finite element analysis

Bone drilling is frequently used in modern surgery operations, especially in fracture treatment. Drilling temperature should be strictly controlled, since when the temperature is 47 °C higher over 60 s, irreversible damages happen to bone. The study investigated the heat transfer of bone drilling by a three-dimensional model based on finite element method. Three principal drilling parameters were studied: feed rate, spindle speed and drill diameter. A parametric study proved that drilling temperature increases once any of three parameters rises. Parameters’ effects on drilling temperature are proved synergistic. An empirical formula of maximum drilling temperature depending on three drilling parameters is given with a sensitivity analysis. To a drilling process of surgical operations, this formula could be used for temperature prediction and optimization of parameters respecting drilling temperature. Furthermore, the intermittent feed drilling is proposed and demonstrated to be very efficient to reduce thermal necrosis to bone tissue.