Periprosthetic fracture of the tibia associated with osteolysis caused by failure of rotating patella in low-contact-stress total knee arthroplasty.

Periprosthetic fracture of the tibial plateau associated with osteolysis resulting from mechanical failure of the rotating patellar component after total knee arthroplasty with the New Jersey Low-Contact-Stress (LCS) knee (DePuy, Warsaw, IN) has not been reported previously. A 67-year-old woman with rheumatoid arthritis of the left knee had a LCS prosthesis implanted without cement, using a rotating patellar component. Seven years later, a fracture of the lateral tibial plateau occurred owing to an osteolytic defect with no traumatic accident. The rotating patellar bearing over-rotated and locked; consequently, wear occurred between the patellar metal tray and the femoral component. Immunohistochemistry revealed CD68-positive macrophages in the osteolytic region and phagocytosis of metal particles. The osteolytic region was filled with autogenous bone, and all components were exchanged and cemented. The patient's condition became satisfactory with relief of pain.