Presentation of the case. The case of a 25 year old woman diagnosed with osteosarcoma of the left proximal tibia is described, which was treated with en bloc resection with a non-conventional prosthesis operated at 8 years old at the Children's Hospital of Mexico; It first required replacement prosthesis at the age of 12 years, the second at 15 years old. At 17 years of age presents new material failure remaining 2 years without support. The patient goes to the consultation of bone tumors at the Naval Medical Center at the age of 19 years to develop a massive metallosis with skin pigmentation and localized edema in his left knee, so new tumor prosthesis is placed. Subsequently patient evolved satisfactorily without data infection, rejection or tumor reactivity prosthesis; The patient is now independent of their daily activities. It indicates that the failure of the prosthesis should be tried revision surgery as soon as possible, discard any infectious process or reaction osteosynthesis material, to avoid injury to soft tissue.
