Fig. 3.

MicroCT section (A), histological slice (B) and 3D pore structure (C) of the diaphyseal cortex at 6 weeks (microCT); histological slice of the metaphyseal cortex at 23 weeks (D); and histological slice of the diaphyseal cortex at 230 weeks (E). The left part of each picture is the endosteal side and the right part is the periosteal side. At 6 weeks: at the periosteal side, circumferential bone plates are present (see arrows in A and B), which are interconnected by radially orientated bone rods. The 3D reconstruction of the pores (C) is made from a rectangular volume within the cortex. This means that the endosteal and periosteal surfaces are not shown. At 23 weeks (D), the endosteal surface had smoothened, but the circumferential plates were still present periosteally (see arrow). In the centre of the cortex, the plates had filled with plexiform bone (see detail). At 230 weeks (E), the inner and outer cortical surfaces were smooth, consisting of circumferential lamellar bone. Secondary osteons were present throughout the entire cortex (see detail).