Supracondylar fracture above a total knee arthroplasty with a posterior cruciate-substituting design presents a challenging problem to the orthopaedic surgeon. The standard treatment using a intramedullary rod is made difficult by the design of the PFC cruciate-substituting total knee arthroplasty (Johnson & Johnson Orthopaedics, Raynham, MA), which prevents entry of a standard supracondylar nail to the medullary canal of the femur. A technique for using an interlocking intramedullary rod to treat a supracondylar fracture above a posterior cruciate-substituting total knee arthroplasty is described. A case is presented illustrating this technique.