Disassembly of a distal femur modular prosthesis after tumor resection

We report and analyze the causes of a disassembly of a newly marketed distal femur modular prosthesis in a 20-year-old man with stage IIB osteosarcoma. The disassembly occurred after discharge from the hospital, after a minor trauma. Because of the unique displacement of the femoral component, sudden operative management was performed. Disassembly should be considered as a potential complication when choosing a modular prosthesis despite improvements in the design of some recent devices. In cases with a substantial amount of functional muscle excised at the time of tumor resection, adequate postoperative rehabilitation is recommended.