Study on the microstructures of skull fracture.

The authors observed the edges of skull fractures under the scanning electron microscope. Many microfractures can be found along the main fracture lines. The width of the microfractures varies from 5 to 100 microns. They may be located either in the external compact bone or between the outer compact bone and diplöe, or in the diplöe. Those within the diplöe form transverse, longitudinal or spiral fractures of bony trabeculae. Collagenous fibre bunches in the bony matrix may be divided or broken and the different layers of collagenous fibre may be separated. The blood vessels inside the skull may be crosscut or longitudinally torn by the fracture lines. Sometimes the torn blood vessels may be drawn out of the Haversian canals. In antemortem fractures, the fibrin networks and red blood cells can be easily found in the depths of those cracks. The possible mechanism of formation of the microfractures and the possibility of differentiation between ante- and post-mortem fractures are discussed.