Figure 6

Plantar calcaneal spurs and their pre-stage are depicted from different donors in the sagittal plane. (A) A surface irregularity (white arrow), which does represent a developing plantar calcaneal spur is shown (Giemsa stain). The black dotted cross represents a matched dot in (C) and (E) for comparative reasons. (B) Silver staining corresponding to A with superficial (dotted black arrow) and deep (curved black arrow) collagen bundles, (C) A spur is present anterior to the estimated border of the calcaneus (red dotted line). (D) The silver staining corresponding to (C) indicates a different collagen orientation of the deep collagen bundles of the plantar fascia attaching to the spur (black curved arrow) when compared to the superficial collagens directed in a sagittal plane inserting posterior to the spur (black dotted arrow). (E) A calcaneal spur is shown with the Giemsa staining and corresponding (F) Silver stain. a, anterior; black asterisks (in E and F), flexor digitorum brevis muscle; curved black arrow, deep collagen bundles; dotted arrow, superficial collagens; p, posterior; i, inferior; s, superior.