In this study, bone transport technique using circular external fixator was used to repair experimentally induced tibial segmental defects in dogs. The results were evaluated on the basis of clinic, radiographic, and histopathologic findings.

Eighteen crossbred dogs of different races, ages and sexes were used. After fixator was inserted, 20 mm long bone segment was removed from the diaphysis of the tibia. Corticotomy was performed on the cranial aspect of the proximal tibia, preserving the periosteum. Following a six days latency period, bone transport was performed at a rate 0.5x12 mm/hours for 20 days, then compression-distraction, consolidation and dinamisation were performed for 7, 40 and 17 days, respectively.

The fixators were well tolerated by these cases. Superficial pin track infections were the most common complications. The cases used their extremities partialy in the second postoperatif weeks and then fully fourth weeks. Edema in legs were observed during first two weeks. The muscles of the left extremity was showed moderate sings of atrophy.

Collogen fibers in the distraction area were seen 2 ^th weeks after distraction and new bone are organized in the direction of the distraction. Bone development in the distraction areas and distal bone union was seen normally in all cases. It was observed in three cases incomplete corticotomy, in three cases deviation, and refracture in two cases in the distal bone region

Bone transport technique used circular external fixator can be satisfactorily used for the recontraction of large tibial defects in dogs.