Fig. 3

Qualitative histology of fusion section with Toluidine blue 0.1% staining illustrated transition two zones. a Proximal transition zone from transverse process (lower-right part) to graft material (upper-left part) is illustrated: cortical bone has typical laminar structure and Haversian canals (H), and ABM granule (G) is surrounded by woven bone. b Distal transition zone from graft material (lower-right part) to fibrous tissue (lower-left) in non-fused mass with a clear gap in between. c Good osteointegration. Hydroxyapatite granule surrounded by woven bone. No foreign body giant cells