Scanning electron microscopy and gel electrophoresis of vascularized periosteal autografts

This study was devised to investigate the morphologic and biochemical sequence of events occurring during early periosteal osteogenesis in vascularized periosteal flaps. A pleuroperiosteal flap based on the intercostal vessels was developed and rotated onto the chest wall in 12 adult dogs. Animals were sacrificed at intervals between 7 and 60 days, and the flaps were removed with the underlying muscular bed. Specimens were studied by tetracycline uptake, gel electrophoresis, light microscopy, and the scanning electron microscope. Osteoprogenitor cells were seen as early as 7 days after transfer. Collagen fiber deposition was vigorous and noted in all specimens with rapid mineralization by 9 to 15 days. There was no structural or vascular interaction between the flaps and the recipient muscular bed. Gel electrophoresis confirmed the presence of type I and III collagen, with an increase in type I collagen over time. The pattern of collagen deposition and the final bony architecture resembled that of woven bone.