The advent of preoperative chemotherapy has made limb-sparing surgery possible in many cases. This 17 y/o female patient with osteosarcoma involving distal femur (same case as the previous 3 images) underwent a limb sparing resection in which the distal femur and adjacent tibial plateau were resected followed by insertion of total knee replacement. Case produced with permission, courtesy of Dr. Frank Gaillard. Radiopaedia. Complete case is here.