[Characteristics of bone regeneration in distraction of bone fragments].

One of the features of distraction osteosynthesis consists in the presence of a zone of permanent growth between bone breaks. Electron microscopic examinations of the permanent growth zone at 14 and 21 days of distraction showed the presence in the zone of cells of three kinds: fibroblast-like cells, osteoblastic elements and little-differentiated preosteoblasts. Fibroblast-like cells and osteoblastic elements were found to have ultrastructural changes of the endoplasmic reticulum indicating the occurrence of intensive synthesizing processes. Specific conditions of blood supply cause hypoxic metabolism with typical enhanced formation of fibrillae which leads to the preservation of the fibrillar tissue throughout the entire period of distraction. The fibrillar tissue in diastace may be considered to be a special growth plate.