Figure 2.

Determining bone ultrastructure organization using polarized light microscopy (PLM). (a) Sketch of the orientation of the fibrils in the osteon, for the three different osteon types (transverse, alternating and longitudinal). (b) Linear PLM (i) and circular PLM (ii) images of the three types of osteons. The linear PLM images exhibit the ‘Maltese cross’ artefact, because of the polarizer–analyser set-up, leading to a ±90° ambiguity in the orientation of the fibrils in the plane of the section. (Images from [5] with kind permission of Wiley-Liss.)