Bone reaction induced by femoral stem of titanium alloy endoprosthesis formalignant bone tumors at the distal femur

We demonstrated radiological evaluations after limb salvage surgery with an uncemented titanium endoprosthesis possessing a rotating hinge-type knee j oint for 7 patients with malignant bone tumors at the distal femur. Althoug h radiographically, cortical hypertrophy and new bone formation at the junc tion between implant and cortex appeared in all cases, there was a small qu antity of subsidence of the implant in all cases. Loosening of the stem was found in 2 patients at 4 and 9 years after surgery. However, after revisio n surgery, the function restored as before. The latest average functional s core according to the system of the International Society of Limb Salvage w as good, being 73%.