Endoprosthetic reconstruction after bone tumor resections of the proximal tibia. The advent of successful adjuvant chemotherapy and radiation therapy protocols for primary malignant tumors and the development of custom-designed metallic endoprostheses has now made possible a successful limb salvage procedure for malignancies of the proximal tibia. Use of the transposed medial gastrocnemius flap, as proposed by Dr. Jean Duboussett of Paris, has been critical to the soft-tissue reconstruction that routinely permits an excellent active and passive range of motion for these patients. This article describes the operative techniques and technical considerations necessary for a successful proximal tibial endoprosthesis reconstruction. 