[Application of Ilizarov's external fixator on the basis of biology]

Ilizarov's biology includes that, in the presence of tension and stress, both regeneration of bone and soft tissues with cellular proliferation and their biological synthesis become vigorous. The Ilizarov's external fixator has five functions namely: compression, distraction, de-angulation, derotation and translocation. The principles of this procedure include: corticotomy instead of conventional osteotomy, placement of 4-5 sets of 1.5 mm wires transfixed in the bones at different levels under tension of 70-110 kg on the circular rings without acute diastasis until the 5 th to 7th day, and then, callotasis-callus distraction. The quality and quantity of the regenerated bone within the widening distraction gap are closely related to the maximum preservation of bone marrow and periosseous blood supply, and a distraction of 1 mm per day and preferably done by 4 times 0.25 mm each time should be emphasized. Experiences in 17 cases of pseudarthrosis and unequal length of leg treated with Ilizarov's technique are presented.