We present a case of total knee arthroplasty in which the patient suffered a transverse stress fracture of the tibia 2 weeks after replacement without significant injury. Plain radiographs were obtained on event presentation. Later radiographic examination showed the fracture and a periosteal reaction. The fracture healed after immobilising the limb in a cast for 2 months. This case illustrates well an insufficiency fracture to the occurrence of stress risers in a weakened bone when subjected to repetitive loading as a complication following total knee arthroplasty.