Fig. 1From: Long-term outcomes of limb salvage treatment with custom-made extendible endoprosthesis for bone sarcoma around the knee in childrenDiagram showing the structure and extension mechanism of the prothesis for patients with the lower limb osteosarcoma. a The prothesis used in patients with osteosarcoma in proximal tibia; only partial cartilage and cortex of the distal femur were resected to implant the femoral joint surface and shaft. b The prothesis used in patients with osteosarcoma in distal femur. c The prosthesis was lengthened by rotating the ring, and the extension of the prosthesis was further secured by inserting two hemicyclic collars between the extension spaceBack to article page