The authors use the "fibula-pro-tibia fusion" (also called Hahn-Brandes Graft, for the treating large bone defects of the tibia shaft. This method is preferred both with congenital partial tibial aplasias with acquired extensive pseudarthrosis defects of the tibia. In congenital cases, grafting of the distal end of the fibula onto the calcaneal end of the foot with careful preservation of the epiphyseal disc, should precede surgery. Large differences in leg length can be treated after fusion surgery by means of elongation osteotomies. Attention is drawn to this method in the second example of pseudarthrosis defect. Lastly the authors mention a further method for mediation of large diaphyseal tibia defects, namely the transplantation of the opposing fibula. This can lead to good results when an aggressive form of fibrous dysplasia is not present, as was the case however in the third example. In such a case the process only heals after removal of the cover of the periosteum as well.