Fig. 1

Preoperative image findings on the extent of osteosarcoma invasion in the tibia of a patient. a The tumor was located at the proximal tibia according to plain radiography. b and c Sagittal and coronal MRI views show that the margin of the tumor was just 2 cm below the joint surface of the knee. d The MRI cross-sectional view indicated that the posterior tibial vessels could be preserved. e HE staining of the tumor tissues