[Callus distraction by an internal bone transport system in unilateral fixation]

The problem of the treatment of bone defects can be solved by distraction osteogenesis as developed by ILIZAROV. This study shows how the bone transport technique can be adapted to every common external fixator while using a new internal distraction system. In 20 dogs a bone defect of 6 cm was performed at the femur. The femur was stabilized with an unilateral frame. A proximal or distal corticostomized bone fragment (length 2.5 cm) was descended through the bone defect (1 mm day). In 15 dogs a new regeneration of bone was observed. The quality of the regenerated bone depends upon stability of the fixation. In 5 dogs with osteotomy and rapid dislocation of the transported fragment no bone bridging was found.