The Ilizarov method.

While the use of external fixators is not revolutionary, the Ilizarov apparatus has dramatically improved the application of the principles of external fixation to the management of bony defects, malunions, infections, and pseudarthroses. Since its formal introduction in Western Siberia in 1951 by Gavril Abramovich Ilizarov, an international cadre of surgeons has employed its methods to pioneer modern limb salvaging procedures. Such techniques are made possible by the numerous advantages, including immediate loading of the limb postoperatively, and the use of healthy viable bone to replace devascularized dead bone "in situ" by osteoclasis, localized transport and osteogenesis. Accordingly, leg length discrepancy, deformity and infected nonunions may all be treated effectively. The basic premise of the llizarov technique is that osteogenesis can occur at a surgical osteotomy site given the appropriate degree of retained vascularity, fixation and quantified distraction. This dogma is a function of many variables which Ilizarov classified into three categories; biological, clinical, and technical. First, biologic variables include preservation of endosteal and periosteal blood supply via corticotomy and stable fixation to prevent shear forces, but to permit axial dynamization with postoperative weight bearing. Distraction should occur at approximately 1 mm. per day divided into four times per day. At the termination of distraction, neutral fixation should be permitted to allow strengthening of the new bone. In essence, the technique fools the body into believing it is a child again. The corticotomy sites now act as physes.