Research Article The Ilizarov Technique

The llizarov circular external fixator was designed in early 1950s [6]. It is a modular device allowing controlled mechanical forces (compression & distraction) to be applies at a pathological bone site. The system uses biocompatible thin wires that are placed in different planes & are secured to modular rings under tension. These thin wires act as a small spring within a more rigid system of rings & concerning rods. In this way the system provides stability against angular, rotational & translational displacements, while it is relatively flexible in axial direction, allowing controlled axial loads to be applied at the zone of osteogenesis [7]. McCoy MT et al. [8] have compared the mechanical properties of four different external devices. They demonstrated that the llizarov external fixator had the lowest overall stiffness but high resistance to bending & rotation strains. It provides a dynamic osteosynthesis system, which prevents harmful (bending, translational & rotational) forces & allows only the useful (axial) forces to act at the osteogenesis site. This probably stimulates bone regeneration. In addition, llizarov apparatus allows multiplanar & multidirectional correction o