Modular knee megaendoprotheses are commonly used devices for distal femur or proximal tibia replacement in tumor surgery as well as for treatment of some periprosthetic fractures around a loose or failed total knee arthroplasty. Structural failures of the prosthesis are well-known postoperative complications and have been reported for various prosthesis types. In the majority of the cases, the polyethylene parts fail. We would like to present an unusual case of a broken femoral component of an MRH® endoprosthesis four years after implantation.