Background: Replacing the entire femur is the replacement of the entire femur of the patient with the artificial femur, and replacement of hip and knee joint. This is a rare, complicated surgery that is often indicated in bone cancer to preserve the lower limbs of the patient.
Case Report: A 24-year-old female patient. Diagnosis: Right femur osteosarcoma. The patient was treated with the preoperative chemicals according to the EOI regimen. The patient had surgery to remove the entire femur and replace it with an artificial femur. After 3 months, the patient could walk on their own with the crutches, no pain, the incision was good. The knee joint ROM is 0°-10°-90°. MSTS score reached 25/30 points. There were no signs of tumor recurrence, infection, dislocation.
Conclusion: This is the first clinical case to be realized in Vietnam. The replacement of the entire femur is a major surgery, requiring a careful evaluation of the injury and an elaborate treatment planning. This is our experience in diagnosing and treating bone cancer.