The use of the Ilizarov concept with the AO/ASIF tubular fixateur in the treatment of segmental defects.

For the treatment of segmental defects of less than 4 cm, cancellous autografting remains the treatment of choice. Pedicled or free cortical grafts (fibula, ribs, iliac crest) often are not strong enough, particularly when used in the femur. Allografts, especially appealing because of the theoretic unlimited supply, should not be considered for segmental diaphyseal defects because they remain dead spacers, remodelled only very slowly and incompletely, and are often complicated by late infection. The technique of distraction histogenesis used by Putti and Anderson, improved and further differentiated towards corticotomy and fragment transport by Ilizarov, is a further possibility of treating long, segmental bone defects. Already clinical and experimental data clearly show that the effect of distraction histogenesis can be obtained using many different types of external fixators. Therefore, we should use as simple a fixator construction as possible. The standard unilateral sagittal frame we suggest is derived from a two-tube AO fixator using only a few additional elements. The majority of cases with segmental defects and minor additional axial or rotational deformities (which can be corrected primarily) can be treated with such a fixator. The quality of the regenerate may be improved with a motorized, continuous transport system and by better soft-tissue coverage using early flaps. Interface healing is very probably improved by cancellous grafting and internal fixation after the transport period, thus decreasing the fixator time.