Modeling and Experimentation of Forces and Temperature Distribution for Bone Drilling with Applications to Orthopaedic Surgery

Bone drilling is widely used in many orthopaedic surgery procedures, including those for correcting bone fractures and for joint implantation. Relatively high forces and temperatures experienced during bone drilling can cause significant damage to the bone, such as, and cell death (thermo necrosis). Therefore, a thorough understanding on and predictive thermo-mechanical models for the bone drilling process are needed.;The main objective of this thesis is to develop mechanical and thermal models for the bone drilling process with applications to orthopaedic surgery. A comprehensive investigation including analysis, modeling, and experimentation of thermo-mechanical aspects of bone drilling is performed for the bone drilling process with applications to orthopaedic surgery. The models will enable prediction of drilling forces and temperature distribution in the bone for given drill-bit geometry, drilling conditions, and material characteristics of the bone.;A new mechanical model for straight cutting-edge drill-bit geometry is developed. A set of experimentation on cortical sections of bovine tibiae have shown that the models are capable of capturing the cutting force signatures experienced during bone drilling. A new thermal model is developed to predict the temperature distribution in the bone and drill bit-chip stream system. The model combines a unique heat-balance equation for the drill bit-chip stream system, an ordinary heat diffusion equation for the bone, and heat generation at the drill tip, arising from the cutting process and friction. A design of experiments on cortical sections of bovine femora has been conducted to measure temperature distribution within the bone during drilling for various machining conditions and hole depths. A new approach is developed for temperature measurement during bone drilling in an accurate and repeatable fashion. The new approach was evaluated by a set of experiments to assess the uncertainly and repeatability.;The anticipated contribution of this thesis research is a comprehensive understanding of thermo-mechanical aspects of bone drilling process and associated predictive models. The developed models can be used to identify drill-bit geometries and drilling conditions that can improve the outcome of orthopaedic surgery by reducing iatrogenic trauma and invasiveness of the procedures.