Ilizarov principles of deformity correction

Abstract

Ilizarov frames provide a versatile fixation system for the management of bony deformities, fractures and their complications. The frames give stability, soft tissue preservation, adjustability and functionality allowing bone to realise its full osteogenic potential. It is important that we have a clear and concise understanding of the Ilizarov principles of deformity correction to best make use of this fixation system. In this review article, the history of Ilizarov frame, the basic sciences behind it, the mechanical principles governing its use and the clinical use of the fixation system are discussed.

Figure 1

Two ring blocks being compressed together. Note each block consists of two rings with two points of fixation per ring. Threaded rods are parallel to each bone segment, preserving alignment of the entire bone. Although this illustration only depicts two connecting rods, four are needed for adequate stability.

Figure 2

By placing the hinge on the bisector line and off the cortex correcting the deformity will cause distraction at the bone ends (A). Positioning the hinge off the bisector will cause a translational deformity (B).

Figure 3

Due to the tibial deformity, the mechanical axis deviation has been moved medially, and as a result a varus deformity is present.

Figure 4

CORA is present at the bisection of the mid-diaphyseal lines, the angle between the two lines denotes the magnitude of deformity.