Are the outcomes of bone transport in the treatment of bone defects in the upper- middle and lower-middle tibia similar?

The aim of the study was to compare the outcomes of bone transport in treating upper- middle vs. lower- middle tibial bone defects. Sixty-two patients with tibial infected large segmental defects treated by bone transport were analyzed retrospectively and divided into distal group (lower- middle tibial bone defects and proximal transport, n=38) and proximal group (upper- middle tibial bone defects and distal transport, n=24). The demographic data were not significant different (P > 0.05). External fixation index (ETI), bone defect union time (BDUT), regenerate consolidation time (RCT), bone healing and functional outcomes evaluated by Association for the Study and Application of the Methods of Ilizarov score, postoperative complications evaluated by Paley classification, and the American Orthopaedic Foot and Ankle Society (AOFAS) score were recorded and compared at a minimum follow-up of 20 months. There were no significant differences in flap repair, follow-up time, ETI, RCT, bone healing, functional outcomes and complications between the two groups (P > 0.05). However, in the distal group, the BDUT was significantly longer, and the AOFAS score was significantly lower than those in the proximal group (17.5±2.5 vs 15.9±3.1 months, 70.0±5.5 vs 72.8±4.8, respectively) (P < 0.05). The overall outcomes of bone transport in treating upper- middle vs. lower- middle tibial bone defects are similar. However, the upper- middle tibia bone defects heal faster than the lower- middle tibial bone defects, and distal transport has a greater adverse effect on the ankle and foot joints than proximal transport. Therefore, traditional distal tibial transport near the ankle joint should be taken with caution.