Fig. 4
From: Demonstration of a novel method to explore osteon tilt in the human femoral cortex
A: Schematic representing the measurements for calculating osteon tilt. Osteon angle measures the vertical off-axis tilt of the osteon as it traverses longitudinally through bone on the z-plane. Osteon angle was measured between the superior and middle layers, the middle and inferior layers, and the superior and inferior layers. Osteon orientation measures the horizontal direction that the osteon travels on the x-y plane. The angle in circular degrees represents the anatomical direction the osteon is moving towards as it travels longitudinally. Although the osteon is represented as a cylinder in the schematic, osteon volume was calculated using the truncated cone formula because of their formation via cutting cone and because osteons extend beyond the viewable area. B: ArcGIS Pro export of a sample of polygons that outline osteons in the lateral cortex. Blue polygons represent osteons in the superior layer, green polygons represent osteons in the middle layer, and purple polygons represent osteons in the inferior layer. Arrows between the centroids show the general path of the osteons as they travel longitudinally through the bone, representing osteon orientation.
