Cutting Behavior of Cortical Bone in Different Bone Osteon Cutting Angles and Depths of Cut

Abstract

Cortical bone is semi-brittle and anisotropic, that brings a challenge to suppress vibration and avoid undesired fracture in precise cutting process in surgeries. In this paper, a novel analytical model is proposed to represent cortical bone cutting processes. The model is utilized to predict the chip formations, material removal behavior and cracks propagation under varying bone osteon cutting angles and depths. Series of orthogonal cutting experiments were conducted on cortical bone to investigate the impact of bone osteon cutting angle and depth of cut on cutting force, crack initialization and propagation. The observed chip morphology highly agreed with the prediction of chip formation based on the analytical model. The curly, serrated, grainy and powdery chips formed when the cutting angle was set as 0°, 60°, 90°, and 120°, respectively. Cortical bone were removed dominantly by shearing at a small depth of cut from 10 to 50 μm, and by a mixture of pealing, shearing, fracture and crushing at a large depth of cut over 100 μm at different bone osteon angles. Moreover, its fracture toughness was calculated based on measured cutting force. It is found that the fluctuation of cutting force is suppressed and the bone material becomes easy to remove, which attributes to lower fracture toughness at bone osteon cutting angle 0°. When the cutting direction develops a certain angle to bone osteon, the fracture toughness increases then the crack propagation is inhibited to some extent and the fluctuation of cutting force comparatively decreases. There is a theoretical and practical significance for tools design and operational parameters choice in surgeries.

Mechanical Properties of a Bone-like Bioceramic–Epoxy-Based Composite Material with Nanocellulose Fibers

“…When the tested specimens were compared, ordinary epoxy specimens and specimens containing bioceramics exhibited different compression fracture patterns. However, the specimens with CNC fractured by generating large particles that were similar to bone chips, which occurred when the bone was cut and as the compressed areas spread widely [ 36 ].…”

Bionic design based on micro-nano structure of osteon and its low-velocity impact damage behavior

“…1 b), and the 5 sub-layers are simplified to a thin layer and a thick layer (Vercher et al 2014 ). The thickness of lamellae effects the stress distribution of osteon (Ismail et al 2019 ), the microstructure of osteon affects the propagation path of microcracks in cortical bone (Gustafsson et al 2019 ) and increase fracture toughness of cortical bone (Liu et al 2019 ; Luo et al 2022 ). Furthermore, the osteon wall thickness decreases significantly in the aged group and X-FEM results indicate that the presence of osteon effects the critical stress intensity factor of bone (Yadav et al 2021 ).…”