Santiago A. Lozano Calderón, Joseph Kuechle, Kevin A. Raskin, Francis J. Hornicek

The megaprosthesis is designed to reproduce the form and function of a removed or lost large segment of bone and accompanying soft tissues. Slow but substantial improvements in the design and surgical implementation of these devices have advanced the capacity to restore patients' functional abilities. The essential challenges include identifying the ideal materials, bonding these materials to bone and soft tissues, reproducing functional anatomy, and adapting to the growing skeleton. Failure of these devices can result from soft-tissue insufficiency, aseptic loosening, structural failures, infection, and tumor recurrence. The history of the use of megaprostheses in the pelvis, proximal femur, distal femur, total femur, and proximal tibia has shown that each anatomic area presents unique challenges. Improvements that have been made over the years will guide the development of the next generation of devices. Despite early high complication rates, these devices are a reasonable choice in the right patient.