Fig. 1: Chemical mapping of HO sections.

XRF maps of resin-embedded slices of human HO excised at A 23 months, B an unknown time and C 36 months post-injury. The inset in (C) is a zoomed-in area, displaying a largely phosphate-free area with nodules of colocalised calcium and phosphate (circled), where a line scan has been taken to quantify the relative levels of calcium, phosphate and sulphur (D), and the ratio of calcium and phosphate (E). For comparison, XRF scans of physiological bone are shown in (F) and (G). Red = calcium; green = phosphorus; blue = sulphur (representing collagen); pink = colocalisation of calcium and sulphur; yellow = colocalisation of calcium and phosphorus (representing calcium phosphate). Insets are corresponding optical micrographs of the HO slices.