LARGE EXPERIMENTAL SEGMENTAL BONE DEFECTS TREATED BY BONE TRANSPORTATION WITH MONOLATERAL EXTERNAL DISTRACTERS

Monolateral frames were applied to five dogs and ten lambs for treatme nt of large segmental bone defects (LSBD) surgically induced in one of their femoral diaphyses. Reconstruction was attempted by bone transpo rt, as developed by Ilizarov. Monolateral frames were used to minimize the drawbacks of Ilizarov's circular device. Radiographic, computed t omographic, and histologic studies were performed. The skin and soft t issues were not a major obstacle for the longitudinal migration of the screws during bone transport. Four months after the operations, heali ng and remodeling of the bone defect was always satisfactory. Histolog ically, the repair of the lengthened segment followed an intramembrano us ossification pattern in its central areas and in the periphery as w ell. At the end of the experiment, the new induced bone had a virtuall y normal diaphyseal bone appearance. Bone transport for the treatment of experimental LSBD can be completed in monolateral frames.