Numerical study of bone fracture healing using a continuum damage mechanics model

Abstract

Managing the outcome of bone fracture healing is one of the most challenging tasks that a veterinary orthopedic surgeon has to accomplish. On top of the difficulties involved with unusual patient morphology, tight budgets and often short times to plan out surgeries in traumatic cases, surgeons have to deal with the delicate trade-off between assuring fracture stability and leaving enough interfragmentary motion to promote optimal bone healing on a case by case basis. While handbooks provide general guidelines for surgeons to follow in some situations, decisions are still often based on their experience and expertise gained on previous cases.

Subject-specific models display the potential to positively alter the outcome of surgical operations by providing surgeons with numerical twins to test treatments on. They have previously been shown to be able to reproduce mechanical responses of both intact and orthopedically repaired bones. A continuation of these works is conducted here. In this thesis, an exploratory study is conducted to assess the capability of a Continuum Damage Mechanics-based remodeling model to represent the healing characteristics found in bone fracture healing. Along the way, the full numerical pipeline from the initial CT image to the Finite Element simulation is didactically presented and improvements made to it are detailed.

Results include improvements to the image-to-mesh pipeline to increase its modularity and robustness. Meshes generated using the improved pipeline show greatly enhanced quality characteristics. Results also show that the extension of the Continuum Damage Mechanics-based remodeling model is able to qualitatively describe the multi-staged nature of bone fracture healing from a mechanical point of view.