THE MANAGEMENT OF MALUNIONS AND MALNONUNIONS BY DISTRACTION OSTEOGENESIS

Abstract

In this paper the results of correction of bone deformities using the llizarov methods, are presented.

Fifty-nine patients, 42 with malunion and 17 with mal-nonunion of tibia or femur were operated upon using the llizarov circular fixator. Another 28 cases were corrected using a unilateral device. There were: a) 30 angular deformities, 18 of which were combined with shortening, b) 21 angular deformities associated with translation and c) 36 complex, deformities including angulation, translation, shortening and malrotation.

Two rings above and two below the apex of the deformity were always required. Different types of hinges were used between them, depending on the type of the deformity. The corticotomy was performed at the apex of the deformity for the majority of the cases. In 18 patients with hypovascular and eburnated bone, or bone covered with soft tissue of poor quality, the corticotomy was done more proximal or more distal to the apex of the deformity. In complex deformities the correction sequence was: 1) correction of angulation and shortening simultaneously, 2) correction of rotation, 3) and finally correction of translation. The true plane of the deformity and the plane of placement of the hinges were determined by a computerized formula that we developed.

The deformities were corrected in all cases in which the hinges were placed at the correct position but in 5 cases we had to re-orient the hinges in order to achieve the correction. The corticotomy or pseudarthrosis consolidated in all cases. Residual leg length discrepancy remained in three patients, not exceeding 135 cm. Great care was taken to prevent complications during operation as well as during the post operative period. However, there were numerous obstacles, problems and true complications. All these were managed aggressively as soon as they appeared. The final results were very satisfactory.

We conclude that the revolutionary llizarov methods can solve bone deformity problems that cannot be faced by the traditional methods. It is critically important to place the hinges at the correct position in order to achieve the desired correction. Our computer program definitely helps to this purpose. The surgeon must always be vigilant in order to prevent complications and to deal with them immediately.