Use of bone transport to treat tibial large segmental defects: experimental study in dogs

The aim of this study was to evaluate the bone transport technique using the Ilizarov external fixator for the treatment of the extensive segmental bone defect induced in the tibia of seven dogs. An Ilizarov frame assembled with one proximal half-ring, one middle ring and one distal ring, all connected to each other, was used. Thirty percent of the tibia and fibula were removed in the medium and distal parts of the diaphyses, between the medium and distal rings. The bone defect was reconstructed by bone transport using a bone segment developed by proximal subperiosteal osteotomy of the tibia between the half-ring and the middle ring. Bone transport started seven days after surgery (0.5mm every 12 hours). Compression was applied in the docking area. The neutral fixation frame period was 14 weeks. The frame was removed at the end of this period, and the dogs were observed for four more weeks. Complications such as intercalary segment deviation (2 dogs) during the trajectory, and nonunion (2 dogs) in the docking area were observed. The functional results were considered poor in the two, fair in three, good in one and excellent in the other dog. The bone transport allowed reconstruction of large segmental bone defect, however, it may have problems during the trajectory of the transport bone segment and in its healing in the docking area.

dog; bone transport; external fixator; tibia; Ilizarov

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