An in-silico bone drilling protocol to control thrust forces using finite element analysis coupled with the constitutive models

Abstract

In orthopaedic surgeries, drilling through bone is most widely used to fix the plates and implants. The uncontrolled large thrust forces generated during bone drilling cause micro-crack, and fragmentation around the local host bone which further loosen the implant and fixation. Owing to the experimental limitation and the risk of infection in handling the bone specimens, conducting experiments with all possible combinations of parameter values and selecting the suitable combination is largely limited. So in this paper, finite element analysis coupled with the constitutive models was used to early predict the thrust forces generated in the surgical bone drilling process. The constitutive models developed in the earlier study, namely, Johnson–Cook, Cowper–Symonds, and Johnson–Cook combined with Cowper–Symonds that consider the strain rate dependence of plastic curve were used for the simulations. Results revealed that the trends of the thrust force values predicted from the constitutive models matched well with the experiments. However, the study showed that the Johnson–Cook model combined with the Cowper–Symonds model predicted the thrust forces with a maximum error of only 9.51% followed by the Johnson–Cook model and Cowper–Symonds model with 15.83% and 21.89%, respectively. The outcomes of the study can be used to predict the thrust forces generated in the bone drilling process, and thus, suitable parameters values can be selected to avoid the mechanical damages around the bone drilling site. The outcomes can also be used to plan and rehearse the in-silico bone drilling trials with any combinations of parameter values before performing the actual surgery.