INVESTIGATION OF BONE DRILLING FOR SECURE IMPLANT FIXATION IN HUMAN FEMURS: TAGUCHI OPTIMIZATION AND PREDICTIVE FORCE MODELS WITH EXPERIMENTAL VALIDATION.

Drilling procedures are important to optimize and ensure the strongest fixation in bone fracture treatment and reconstruction surgery. The mechanistic force models currently available for bovine bones, human spines and human mandibles are not relevant to perform drilling through human femurs. The present study addresses this lack of information and aims to develop the predictive force models for drilling human femurs at different regions and directions. In this study, 10 freshly harvested cadaveric human femurs were included, and a surgical drill bit of 3.2 mm diameter was used to make 4 mm deep holes. Different spindle speeds (500, 1000 and 1500 rpm), feed rates (40, 60 and 80 mm/min), and apparent density between 0.98 and 1.98 g/cm3 were considered. The optimal parameters f 3 s 3 , f 2 s 3 , and f 1 s 3 respectively obtained for longitudinal, radial, and circumferential direction could minimize the thrust forces in bone drilling by up to 7.70, 10.50, and 16.20 N, respectively. Validation study demonstrated that the force model developed could predict the thrust force from computed tomography data sets of the patient, only with 5.05%, 6.74%, and 4.91% as a maximum error in longitudinal, radial, and circumferential direction. This important tool can assist to perform complicated surgical operations. [ABSTRACT FROM AUTHOR]