Background: Bone cutting is a well-known surgical procedure in orthopaedics and dentistry for fracture treatment and reconstruction. Common complications associated with the process are mechanical damage linked with excessive levels of penetration force. Larger forces may produce minor cracks in bone which may seriously affect strength of fixation and may delay the healing process.
Objective: This paper investigates cracking behavior in the microstructure of cortical bone in cutting using experimental and numerical techniques.
Methods: Experiments were performed on cortical bone to study the mechanics of crack propagation and evaluate the extent of crack with the drilling force and amount of penetration. Finite element (FE) simulations were performed to visualize the extension and arrest of the cracks in bone microstructure.
Results: The length of crack was found to be strongly influenced by the drilling force and amount of drill penetration. Osteon were seen to deflect the cracks at their boundaries. Crack propagation in bone microstructure was observed to depend on anatomical direction. Numerical simulations predicted the direction of crack propagation and found osteon boundaries to act as barrier to the cracks.
Conclusions: Lower drilling force may be used in cutting the bone to avoid cracks in the bone tissue. A detailed FE model based on fracture data of cortical bone is to be produced to simulate cracking of bone microstructure.
Keywords: Orthopedics; bone drilling; crack; drilling force; finite element simulation; micro-CT; scanning electron microscopy.